Honda CB77 Shop Manual

MOTOR
MANUAL
REFERENCE ONLY
THIS BOOK MAY NOT
BE BORROWED
l
C19389032.
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Mo+or Co / ~co ... ~
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C1 93S90 32
HONDA MOTOR CO., LTD.
Technical Books
Christchurch
20 WINDMILL CENTRE
RICCARTON
PHONE/FAX 348-0220
PREFACE
This Shop Manual contains general data and information , and procedures relative
to vehicle maintenance, over-haul and repairs for the models covered by Honda 250
and Honda 300 equivalent to Model C72· C77, CB72· CB77, CS72' CS77.
(3 c:>Sc.c)
Therefore,
information
in
this
manual
will be suitable instruction for servicemen
and mechanics of Honda to assist them to efnciently se rvice and repair these machines .
Now, in this case, mechan ica l arrangement means to repair a veh icle when it is
out of order and restore it to the ordinary state as well as to prevent it from any
HONDA 250 MODEL C72
tr ouble by periodically in specting the vehicle.
The contains of th is book are divided into nve chapters, including main standards,
disassembly-assembly, const ru ction, wiring diagram and trouble shooting.
Each chap ters are separated into sections.
is divided into 2 sections - Engin e and Fra me.
Disassembl y.assembly Ilhe 2nd chapte rl
The section of Engine is described both
model C72· 77, CB72· 77, but that of Frame is done only mode l CB72· 77.
In regard
to
the
Frame
of
mode l C72· 77, please refer to
the
previously
published Shop Manual fo r H ondo 125· 150.
An
HONDA 250 MODEL C S72
effort
has bee n made to produce a manual avoiding fundamental principle
and theory by expla ining th e actual mechanism.
Special emphasis has been placed an illustrations and charts to make it easy for
the service man to understand without reading every line .
We hope this will
some use to you.
This manual will be revised without notice.
January, 1960.
HONDA MOTOR CO., LTD.
TECHNICAL SECTION
EXPORT DEPARTM ENT
No. 5- 5, Yaesu-cho , Chuo.ku,
Tokyo , Japan
HO NDA 250 MODEL CB72
Ge.-
"?..9.2.~775
HON
18 JU L 1996
be
of
CONTENTS
MAINTENANCE STANDARDS, C72· 77
For
maintenance
operation
for
HONDA
250 . 300, Maintenance
Standards,
specification and dimension are listed hereafter for reference .
I.
GENERAL PERFORMANCE .... . • . ....... , ..... , • . . . . , . • ......... • .. . ..
2.
ENGINE
EXPLANATION:
Maintenance Ite ms
Items to be inspected, se rvice-wise.
I..
Standa r d Valu e
Thi s indicates the manufact ur er 's standard size or the stondard size
after newly assembling or adjusting, and shows th e size-limit of
complet ed part in the permissible limit of ad justment.
Repairin g Limit
Rem ark s
A.
Cylinder, Cylinder Head .. ......... ...... .•.• •.. . . . ... .. .•. ...
B.
Crank Shaft IPiston. Connecting Rodl .... • •....•...... . .. . . .. •.. .
2
e.
Cam, Timing and Valve
... . ... .. . . ..... . . . •••........... , • . . .
3
D.
Upper Cronk Case . .. .... . ......•..... . . ••.... . . .... . . . . . .. .
5
E.
Clutch, L. Crank Case C over ....• •.... • •................• .....
5
F.
Transmi ssion . . . .... . . . . . . . . . . . . . • . . . . . . . . . . . . .. . . . . . . . • .. .. .
6
G.
Magneto. Contact Point . .. ...•• ....• .........•..........• •...
7
H.
Oil Pump. Oil Separator ..... .... . . ... .
.. .... .. . .. ........ .
8
,
Unusable wear limit of parts requiring correction or repla cemen t,
I.
Kick, R. Cronk Case Cover ........ .. . .. . • .......••..... . • •. • ..
3
function.wise.
J.
Under C ronk Cose and Change
....... . . ... . ................ . ..
8
A.
Handl e .... . ...... . ..... . ... . • •.... .•..... . . . , .. .. . .. . •....
9
B.
Front Cus1ion ..... ....... . .. . . . .... .... ...•
9
e.
Front Fork, Steering, Tonk
D.
Fro me Body .... .. .... . ....•....•...... . •.• • . , . .•...........
10
E.
Saddle, Stand
........... ..... , . .. . .... .. ............ .. . . . . . .
11
F.
Rear Fork , Chain Case
.............. .. ...... . .. . ..... .. . . . . .
11
G.
Rear Cushion
. . .......... ... .. ..... . ...................... .
11
H.
Front Wheel ....••. . . . •.... •..... ....... •• • •. . ...•.... . • .. . .
11
I.
Rear Wheel ....•...... . . . .•. . ......... , • . . • . . . . . • . . . . . • • . . .
12
3.
Unmarked numbers are ru n unit and inch unit shown underneath,
and others according to th e unit indicated.
UNIT IN CHART:
Unmark ed numbers are m/m unit and inch unit shown underneath,
and others according to the unit indicated.
,J,.
FRAME
... . •. . ...•• . . . . . .. •..
10
MAINTENANCE STANDAR DS (Mode l C7 2 )
This maintenance standards is lisled only about the doto of Model C72. In this list ,
dimentions without units indicate "mm" lupper step) and ,. inch" (down step),
and others acco rding to the units indicated.
1.
G ENERAL PERFORANCE
IIe m
I
Comp ression pressu re
Standard
I Repeidng limit I
8.5 kg/ em'
120.87 Ib/ in'
42-45 km/
26.04 - 27.90
mile/
120 ee/ l 000 km
or less
120 ec/620 mile
130 km/ h
80.60 mile / h
7.0
99.54 Ib/ in'
29
17.98
e
e
Fuel consumption
l ubricant consumption
Max. speed
Check with kick
35 km/ h 121.7 mile/ hi
200/ 1000
more
200/ 620 mile
90 less
55.80 mile
I
T he posture is leaning fo rward one
thi rds of the body
I
2.
Remarks
"".
ENGINE
A.
Cylinder, Cylinder Head
II e m
Cylinder
I
Inner dio .
Standard
53.99-54.00
2. 1255-2.1259
within 0.001
Max . out of round
Toper
I
Over size of cylinde r
Ove r size
Cylinde r head valve
Width
0.25
0.00984
1. 0-15
I 0.0393-0.0590
I
45 0
sheet
Angle
Compression ratio
C ylinder head gasket
within
0.001
I Repei,ine limit I
54. 1 more
2.129
0.05 more
0.00019 0.05 mOre
0.00019
3 category of 0.25
10.00981 ove r size
2.0 more
0.0787
8.3
0.326
Flatness
within 0.03
surface
Cylinder head gasket
Thickness
I
Cylinde r stut nut
Tightness
I
I
0.0011
1.0 - 1.1
0.039 - 0.043
2.1 kgm
15. 189 ft Ib
Remarks
0.06 more
0.0023
The capa ci ty of the
combust ion chom.
be r, 16.94 ee
In case of binding
B.
It e m
Piston
Top diameter
I
, Max.
I Out
I
I
Piston & cylinder
+0
54_0.02=D
dio.
D-10. 140. 161=d
of round
Dia.
Pisto n over size
Over size
Taper
Top · 2nd ri ng
Thickness
I
Width
Tension
I
I
ring & ring
Clearan ce
groove
Oil ri ng
Thickness
Width
I Tension
I
I
Oil ring & ring groove
Piston over size
Piston pin
0
I
End gop
Clearan ce
Ove r size
Out. dio.
Total length
I
I
II
I
15.0 -15.0006
0.59 - 0.5907 !
0.25
0.0098
D-0.08d-0.08
D-0.0031 d-0.003
2.4 -2.6
II
0.094 -0.1 02
1.780-1.795
I
0 .0700-0.0778 I
0.75-1.05kg !topl I
0.70- 1.00kg 12ndl
I
End gop
53.5 le ss
2.106
53.9 less
2.112
1.653 - 2.315 Ib
1.543-2.205 Ib I
iI
,
0.15 - 0.35
0.0059 - 0.0 137 I
I
0.01-0.04
0.0003- 0.000 15 I
2.4-2.6
0.0944 - 0.1 023
2.780 - 2.795
0.1094-0.1100
0.7 - 0.9 kg
1.5435 -1.9845 Ib
0.1-0.3
0.0039 - 0.0118
0.01-0.04
0.0003 - 000 15
0.25
0.0098
14.994-15.0
0.5903 - 0.5905
45.5-45.7
1.7913-1.7992
0.1 more
0.0039
15.05 more
0.5925
I
Piston pin & piston
Remarks
:
53.55 - 53.60
2.108-2.110
Min. clearan ce
Pist on pin
II Repalflng
.. lImll
· I
Standard
D-IO.005 0.0061=d
Top· 2nd
It e m
Crank Shaft (Piston , Connecting Rod)
The progressive
direction of the
lower ports of skirt
Connecting
I
Clearance
I In.
cod
dio.
small end
Con. rod small ent) &
Clearance
piston pin
Con. rod small end
Swing
Lower end of can. rod
Axial cl eara nce
./
Big end · small end of
Amount of parallel
Distortion
category of
ove r size
Boronser weight
Out. dio.
crankpin
2.3 less
0.0905
1.7 less
1.3230 less
R. L. crank shaft
Dio. of shaft
Cronk shof t bearing
Axial clearance
Radial clearance
Tangential tension
In case of binding
Crank shaft
Max. swing
combina tion
Cam chain
0.8 more
0.314
0.1 more
0.0039
2.0 less
0.0787
2.7 less
0.10629
0.5 less
1.I025 1b
0.8 more
I
I
C.
length
0.0031
In. valve guide
In. dia.
Ex.
valve
Overall length
Out. dio.
of
stem
I
Thickness
of head
ca tegory of
In. valve
Max. amplitude 10
axial direction of
I
0.0196
0.05 mOre
over 0.1
0.00078
0.0039
within 0.02
ove r 0.1
0.00078
24.99-25.00
0.9838 -0.9842
30.82-30.86
1.213-1.215
0.005
0.00019
0.014 - 0.016
0.0005 -0.0006
0.03 less
0.0011
I
723.0 -723.8
28.46-28.49
cronk pin
0.5 more
A, leng,h
100 mm
At length
100 mm
0.0039
of
13.93 inl
of
13.93 inl
I 24.95 or Ie"
0.9822
I
30.6 or less
1.204
Cen ter bearing
Over 0.1
0.0039
Over 0.05
0.0019
,
In case of supporting
center bea ring . th e
swing of both ends
over 0 1
0.0039
Ove r 728
28.66
Standard
I
I
IRepoicing limi' I
I
Ex.
In case of binding
over size
0.08 more
within 0.02
I
Tangential tensi on
0.25 10 .00981
0.00196
15.08 more
0.5936
Cam· Timing and Valve Mechanism
tIe m
3
In cold, push in
softly by fingers
0.05 more
0.118
0.07 -0.33
0.0027 -0.012
0.006 -0.016
Overall length
Out. d io. of stem
7.0 -7 .01
0.2755 - 0.2759
,
88 .65 - 88.85
3.490 - 3.498
I
6.97 - 6.98
, 0.2744 - 0.2748
I
I
1.0
0.03937
89.18 - 89.38
3.511 - 3.5 18
6.97 -6 .98
0.2744 - 0.2748
I
3
2
0.012
0.0004
15.043
0.5922
0.049
0.00 19
I
0.031 4
0.1 more
00039
14.95 less
0.5885
Overall
Remarks
I
0015.016 0.5911 0.0 16 0.0006 -
can. rod
0.25 1000981
0.0669
0.6 kg le ss
I
I
3
I Repoicing Umi' !
3.0 morc
Diagonal clearance
,
Standard
I
over 7.05
0.2775
88.2 or less
3.472
6.95 or less
,
I
I
0.273
0.5 or less
0.001968
88.7 or less
I
I
3.492
6.95 or less
0.273
Remarks
r1e m
In . dia.
1. 0
0 .03936
Thickness of head
Ex. In. valve
Ex. valve stem and
Width
C lea rance
guide
In. valve stem and
C learan ce
guide
Valve spring ou l er
Fr ee length
Te ns ion
Valve spring ou te r
Valve sp ring inner
Ten sion
Co m shoft
Shoft dio.
Bend of sho ft
Hei gh t of cam
Cam shaft and bearing
Clearan ce
of jou rnal
Valve timing Ex.
[ at 1.1 mm (0.0431 of
l ift length)
Opening angle
less
0.0019
Rocker arm c rank pin
Out. dia.
0.0787
I Clearance
ove r 0.08
to rocker
orm
0.0031
Ex. In. valve adjust
Toppet clea rance
Cam choin tensi one r
Free length
over 0.07
0.00275
42 .3 o r less
spring
1. 665
Tension
At 34.5 mm (1.351 of
binding leng th
I At 27.5 mm 11.081 of
t
I
wilhin 1.
0.03937
34.66
1.364
3.9-4.3 kg
14 .5-15.5 kg
8.59-9.48 Ib
31.97-34 .17Ib
Decline
Or
Over 20
1.0 - 1.5
0.0393 - 0.059
0.02-004
0.0007 - 0.00 15
0.01-0.03
0.00039 -0.0011
43.82
1.725
11.6-12.4 kg
24.2-25.8 kg
25.57 -27.3Ib
53.36 - 56.8 Ib
Decl in e
Free length
0.5
~~5;ore
max. lifl
I
Cam cha in tensi one r
Oul. dio.
roller
D.
Item
mm
At 24.5
mm
0.0393
19.98-19.99
0.786-0.787
withi n 0.01
In dia . of
ox Ie
Com choin gu id e roller
Out. dia.
pi n
Chain gu ide roller
In. dio .
0 .05 more
0.0003
26.98-2 7.02
001062-001063
I-I
1+1
0.003-0.Q3
0.00011- 0.00 11
before lower
I
0.0019
26.7 less
001 05
E.
r tern
I
after upper
Clutch cen ter
In. dia.
[ a t 1.1 mm 10.0431 of
l ift lengt h)
Ope ning angle
dead point 10
Closing ongle
Rocker arm
74.766
2.943
Bottom diameter
Ta fix steps
on slippe r face
Out-r oun d swing
,
I N on-clearance
Pri mary drive sprocket
Bottom diameter
Clu tch friction disc
Thickness
0
74.2 less
2.922
In case of having
0.3 more
some trouble on
0.0118
slipper surface
Strain
I
4
25 .0 - 25 .021
21.0 - 21.08 4
0.984-0.985
0.826 - 0.830
withi n 0.1
0
aft e r lowe r
dead pcint 25
Com sprocket
P. 6 com
bef o re upper
I
I
N on-cle aran ce
dead poin t 10°
Valve timing In.
Standard
I
P. 6 cam
dead point 25 °
Closing angle
IRepair ing limit I
Without injury of
rubb e r
Remar ks
34.2 more
1.346
12.2 mo re
0.4803
13.9 less
0.547
14 .1 mo re
0.5551
I
I
Clutch· L. Cr ank Case Caver
0.08 mo re
0.0031
±5°
Standa rd
Cool sta te
70 less
2.755
10 less
22.05
58.5 less
2.303
34 .0-34.02
1.338 - 1.339
12.0 - 12.01
0.472 - 0.473
13.966 -13.984
0.549 - 0.550
14. 0 -14 .0 1
0.5511-0.5518
(0 .96t of
ma x. lifl
0059
19.95 less
0.785
13.1 mo re
0.515
12.9 less
0.5 078
0.1 more
0.0039
I
In dia.
H o le, shift drum
1.5 mo re
within I .
out of
stonda rd
I
(1.2 41 o f
binding len gth
13.0 - 13.027
0.51 1 - 0.522
12.966-12.984
0.510-0.511
0.16 - 0.061
0.0006-0.0024
0.09-0 .11
0.0035 - 0.0043
73
2.874
16.0 - 16.2 kg
35 .28 - 35.71 Ib
59.2-59.8
2.33-2.35
Rema rks
Upper Crank Ca se
33.4 less
1.314
At 31.5
I Repairing limit I
Standard
I
Remarks
Standard
Item
0.0039
39.11-39.21
I 1.5397 - 1.5436
4.8 -4 .9
0 .1889 - 0.1 929
within 0.2
0.007B
I Repa iring limit I
I
,
I
24 .9
20.9 less
0.980
0.822
0 .2 mo re
0.0078
38.3 less
1.5078
4.4 less
0.1732
0.5 mo re
0.0196
I
Remarks
Item
Remarks
Standard
It em
Rad;u s ploy
Clutch plote
W;dth of hook
Teeth and outer of
Rotary play
within 0.2
Free length
0.0078
33.4
1.3149
clutch pressure plate
Clutch sp ri ng
0.0314
32.4 less
1.2755
15.0 less
123.0751
19.8 kg
33.736 ~ 36.823
In. dia.
Bush
17.1 34
0.672 ~ 0.674
Out. dia.
17.094 ~ 17.112
In. dia.
14.413 ~1 4.431
Sta ndard
15 &
Capacity
I
At 25 mm 10.981 of
binding len~h
Counte r shaft & bush
0.028 ~ 0.04
Clearance
0.00 11 ~ 0. 0015
0.01 ~ 0.098
0.00039 ~ 0.0038
At 23 mm 10.9 I of
Ib
max. lift
0.396 gol U.S.
I Repo; do 9 limd I
C o unter shoft & C2
Rotary ploy
I
Remarks
l ow gear bush & 14 mm
Clearan ce
bush
K;ck sta rle r spindle
O ut. dia.
0.00078 ~ 0.0022
14.341 ~ 14.353
0.564 ~ 0.565
standard
I
In cronk and mission
K; ck starte r sp indl e &
0.9826~
Moin shoft and M2
0.983 4
0.07 ~ 0.074
Clearan ce
gea r
Axial direction of main
0.1
C le ara nce
Turning direction of
~0 .75
0.0039~0.0295
shaft
0 .03 ~ 0.078
C learance
M3 gear
Teeth surface of ge ar
0.089 ~ 0
A xis ploy
178
0.06 ~ 0.09
Clearan ce
To p gear bush 20 .5,p
In . dia .
20 .5 ~20.52
20.6 more
Top gear bush & main
shoft
Clearan ce
Drive sprocket ·
Bottom dia.
0.8070 ~ 0.8079
0.04 ~ 0.082
Rota ry ploy
Main shaft & top gear
Axis ploy
0.5 more
71.51
65.649 ~ 65.776
2 .814 ~ 2.815
136 0 6~
Bott o m di a.
sprocket
0.03 ~ 0078
71.5~
,
Primary driven
2.584 ~ 2.589
0.811
0.1 more
0.0039
70.5 less
64.7 less
2.77
2.54
,
,
136.16
5.356 ~ 5.360
0.005
bearing
0.019
135.3 less
5.326
01 more
0.0039
0.0023 ~ 0.0035
Kk k spindle pole
R- part
Kkk spindle pole
Free length
14
0.5511
l oosing
5~IO
0. 1 968 ~ 0.3937
I
G.
0. 15 mo re
I
!
0.0059
0.0118
2.0 less
0.787
Magneto, Contact Point
I
Item
Standard
I
Conta ct breake r
Tension
arm spring
Repairing limit
0.85 ~ 1.05 kg
0.44 1 ~ 0.882
I
I
Gop
Ignition timi ng
Cran k angle
Spo rk ad v'a ncer; be-
Ro tary number
0.3 ~ 0.4
0.0 118~ 0.0157
Spline ports
ginning of ad vanc e
angle
Spark advancer; end
of advance angle
Rota ry number
25.9 mm 11. 0191
out of
standard
after upper
dead point SO
1100 r.p.m.
3000 r.p.m.
In ca se of
24.5 mm 10.9641
of binding length
In case of
1.874 ~ 2.315
C ontac t point
.
Rema rks
I
0.2 ~ 0.4
7
6
I,
0.677
0.1 more
0.0039
14.25 less
0.561
I
1
with step
0.3 more
sp ri ng
Primary chain
0.2 more
18.018
0.708 ~ 0.709
18.0~
In. dia.
each bush
1.2 more
0.0472
0.1 mo re
0.0039
0.0078
18.1 more
0.712
relating to mission
Top gear bush 18,p
24.9 less
,
0.980
0.1 mo re
0.0039
I
0.01 96
17 .2 more
0.02 ~ 0.058
1
24.959~24 . 98
Out. di a .
,
0.5 mOre
,
1 7.13 ~ 17 .15
In. dia.
1
out of
I
14.45 more
0.5689
0. 1 more ,
0.0039
0.674 ~ 0.675
ing oil
M ain sh aft
0.677
0.567 ~ 0.568
l ow gear bush
Mi ss io n case lubri cat-
17 .2 mo re
I
0.672 ~ 0.673
Transmission
I
I
0.960
17.084 ~
gea r
It e m
Remarb
0.05 mor e
24.4 mo re
0.959 ~ 0.960
43.6591b
F.
I
24.37 ~ 24.38
0 .8 more
15.3~16.7kg
Tension
0.0 1 ~ 002
In. dia.
C ounter shaft
0.0196
13.0 less
. 0.5118
0.0078
13.7 ~ 13.8
0.5393 ~ 0.5433
1 Repa iring limit I
1
0.5 more
wi thin 0.2
Stra in
Standard
I
out of
standard
of max. lift
.
It e m
I
Standard
!Repoi'ing limit i
40 °
37 ° _4 3°
Shih drum & hole o f
3 needle gop
8 mm mo re
7 less
0.2755
Charge curren t
0.3149
2.0A-3.0A
ch aracter
Magneto charging
2A less
character
H.
0.8 more
0.5
0.0196
Gap
Dynamo starter & rotor
0.0314
I
I
I
,.p.m.1
At 3000 r.p.m.
I, Ai r-gop
I
Shift fo,k
In. dia. of hole
lin ra dius}
)
Thickness at end
Oil pump drive gea r
0.01 less
0.0039
0.4
0.0157
0.025-0.05
Back lash
Oil pump drive gear
& cen l e r c ronk ge ar
Thickne ss
Oil pump po ck ing
Clearance
Add endu m and interr,al
0.106-0.210
0.0041 -0.0082
0.089-0.04
Back lash
Oil pump gear
Clearan ce
Side a nd side cove r of
oi l pump gea r
I.
Kick starter joint & hol e
o f c ronk case cover
Kick sta rte r spring
Standard
I
I Clearance
I T orque
I
I
47.6 kgm
344.290 fl Ib
01 mo re
0.0039
0.5 mo re
0.0196
A.
I
I
O.15more
0.0059
0.1 mo re
0.0039
Throtlle
I
wire differ .
ence between outer
& inne r
I
. Repoi'i ng limit
I
Remarks
Shih dr um
I
Length
I
Brake le ve r
Play
Clulch w ire ditto
Lenglh
Clulch lever
Play
B.
0.0196
40 less
289.32
33.95 -33.97
1.336 - 1.337
I
I
I
Repa i ring Limit
I
I
I
Remarks
I
2-4
0.0787 - 0. 157
61
2.4015
out of
sta ndard
25-30
0.984 -1.1 81
11 8
4.645
15-25
0.590 - 0.984
out of
standard
In ca se of use
It e m
Repo i,ing Limit
33.9 less
1.334
Standard
I
I
bush
Pi vo t bush & suspenRem arks
O ut. d ia .
Clearance
I
26.04 - 26.07
1.025 - 1.026
0.037 - 0.08
sian arm
Overall length
24.5 -24.6
0.964 - 0.968
9
8
D8 X P1.25
Ch eck by external
1
periphery
I
Check by lever end
Che ck by lever end
,
out o f
st andard
I
I
Front Cushion
Pi vo t coll ar
dia.
D6 X PI.O
0.5 mo re
\
I Out.
Standard
II
Pla y
Th ro ttle g rip
Fr ont cushion under
Standard
0.00787
8.50 - 8.515
9.0 more
0.334- 0.335
0.354
34.0 - 34.02
34.1 more
1.338 - 1.339
1.34
4.9-5.0
4.5 less
0.1929 - 0.1968
0.177
0.1 within
0.8 more
0.0039
0.031
0.5 - 0.7 kgm ,l out of
3.616 - 5.063 hlb
sta nd ard
1.7 -2.0 kgm
12.29 -14.46 fllb
Handle
It e m
Under Crank Case and Change
It e m
0.2 more
FRAE
I
0.08 - 0.205
11.9 less
0.4685
I
I
Kick' R. Crank Case Cover
It e m
J.
0.05-0013
Clearance
Gear pin and gear
3.
I In case of binding
i
I
Remarks
Adjus t by packing
0.0196
wal l o f o il pump gear
Torque
I
0.5 more
I
end
I T o rq ue
Stud
0.1 more
0.0039
0.063 less
G ea ri ng eccentric
Bend at
Se lli ng stud bolt of
upper, unde r crank
case
Remarks
Repolring l imi t
Standa rd
Shih drum
Groove width
1500~800
Oil Pump' Oil Separator
II e m
Clearance
cronk case
By kick
IRepo idng limit I
11 .966 -11.984
0.47 11- 0.4718
0.Q25 - 0.075
port
ad vance a ngle
Magn eto spark
Siandard
I
Out. dia. of axial
Crank angle
Spark advan cer; max .
l ie m
Remarks
IRepoidng lim it I
I
out of
standard
Remarks
Standard
It e m
I
Repaidng limit
I
E.
Saddle' Stand
Remarks
Piv o t bush & collar
Cleo'once
0.016 - 0.07
Stroke
60 .3
2.374
38 - 45 kg
83.79-99.22Ib
39 cc
Front cushion dampe r
Damping force
Od
capacity
Side & main stand
Free length
Te nsion
Foil
278.8
10.976
127.5 kg
281.131b
1
0
within
spring
20 less
44 .10
25 less
Food width
By 0.5 mlsec
Standa rd
Steering head stem nul
Steering
head
Torque
Angle
6.5 -7 .5 kgm
47.014-54.2 ftlb
90 °
268 less
10.551
110 less
242.55
Ite m
ou t of
Repairing limit
Ho le
Rear fork pivot bush
Out. dia.
Dr ive chain
Amount of
Remarks
G.
Capa c ity
II e m
standard
Stroke
Rear cushion
head pipe
75
2.952
11.8
3.115 gal U.S.
Damping force
Oil capacity
e
Rear cushion spring
Free length
Tan gential angle
fork pivot bolt
bush
Standard
In. dio.
Repairing L mit
standard
! Repa iring
Standard
I
0.0098
12.2 - 12.3
0.480 - 0.484
~
Remarks
,
61
2.401
50-56 kg
110.25 - 123.48Ib
39 cc
I
30 less
60. 15
30 less
I AI 0.5 m/ sec 119.681
of piston
II
218.4 - 218.9
207 less
8.149
8.598 - 8.618
143 kg less
150 - 166 kg
330.75-366.03Ib 315.3151b
I out of
1 0 within
lIe m
12.6 more
I
standard
While spindle oil ~60
I
I
I
I
I
Front Wheel
Standard
I Repa iring
limil
0.496
Front wheel hub ball
Axial play
0.005 less
0.1 more
0.00393
0.01-0.D2
0.05 mo re
bearing
Radial ploy
10
limit
Remarks
H.
1/ 4"
Out. dio.
95 teeth
ou t o f
I
II e m
Rear
12 .4 more
0.488
Angle between
Frame Body
Sleel boll
I
12. 1- 12.2
0.476 - 0.480
28.0-28.03
I . I 02 - I. I 03
10-20
0.393-0.787
sog
T ension
D.
Remarks
Repa i ring Limit
Rear Cush ion
Rear cushion d..Jmper
Fuel lonk
Standard
I
end
out of
60 °
Trail
oul of
standard
I
Rear brake torque link
trident and
Coster
Remarks
Rea r Fork· Chain Case
Front Fork· Steering · Fu e l Tank
It e m
I
119.68 inl of piston
White spindle oil #60
standard
C.
38 kg
83.790 Ib
20 - 30
0.787-1.181
Max. tension
Broke pedal
F.
Front cushion spring
l·Lmlt
0.3 more
0.0118
Front cushion
I Repomng
..
Standard
l ie m
II
Remarks
.
It
t t em
Front broke panel
spacer
Overall length
Overall length
colla r
Thickness
Brake cam
Front broke
shoe
Out. dio.
Fr ont brake lining
Thickne ss
Brake drum
Broke
shoe
In. dio.
spring
Free
length
Front ax le
Out. dia.
Front axle
Bend
I Repaid ' 9 Limit I
21.9 less
0.8622
I
Front lire
Ai r pressure
0.2 more
0.0393
1.5 kg/ em'
2 1. 330Ib/ in'
I
I.
Free length
Rear brake eam
Thickness
pedal
Foo t width
Rear whee l rim
l ateral deflect ion
Rear tire
Ai r pr essure
174.1 -1 74.3
6.854 - 6.862
3.5-4.5
0.137 - 0.177
27.88
1.0976
11.9 - 12.1
0.468 - 0.476
20 - 30
0.7874 -1.1 8 11
t .O within
0.0393
2.0 kg / em'
28.44 Ib/ in'
Bo th ends suppo rt on
V block, measure
be nd at cen te r part
3.0 more
1.0 within
•
Rea r brake shoe spring
~
0.0078
Lal eral deflection
Thickness
Rear brake
0.05 within
Front wheel rim
Rea r broke lining
Cutter out. dio.
2.5 le ss
0.0984
176.0 more
6.929
58 mo re
2.283
14 .9 less
0.586
0.118
out of
stondard
I
I
I
Rear Wheel
It e m
Final driven sprocket
Rear wheel
hub
Standard
I
Bottom di e.
Axial ploy
•
IRepaid'9 limit I
145.76
5.738
0.005 within
1
Radial play
Rear axle dista nce
Ove rall
length
Overall
length
colla r
Reer axle sleeve
I
I
I
I
I
Rea r wheel ax le
Out. dia.
Rear b rake sh oe
Bend
0.01 - 0.Q2
73.8-74.2
2.905-2.921
9.5-9.7
0374-0.381
16.9 - 17.0
0.665 - 0.669
0.05 withi n
Remarks
144.7 less
5.696
0.1 more
0.00393
bearing
0.05 mare
I
I
16.85 less
0.661
0.2 more
0.0078
13
12
Repairing lim it
Remarks
Remarks
O ut. dio.
21.972-21.993
0.8650 - 0.8658
34.9 - 35.1
1.374 - 1.381
49.8 -50.2
1.960-1.976
11.9 -12.1
0.468 - 0.476
174.1-174.4
6.854 - 6.866
3.5-4.5
0. 137 - 0.177
174.8 -175.2
6.881 - 6.897
55
2.165
15.0
0.5905
Out. dio.
Front axle distance
Standard
I
Standard
e m
Cutter out. dio.
3.0 less
0.118
32.0 more
1.259
out of
standard
3.0 mo re
0. 18 1
out of
standard
,',,
CONTENTS
MAINTENANCE STANDARDS,CB72· 77
For
ma intenance
ope ration
fo r
HONDA
250· 300,
Maintenance
1.
GENERAL PE RFORMAN CE .. . •... . •.... . • •. . . . ...•. . .. .. . •.... .. •.....
2.
ENGIN E
19
Sta ndards,
specification and d imension are listed hereafter for re fe rence.
EXPLANA'((ON:
... .. ........ . .. .... . .. . . .. . .... .. . .. .
19
A.
Cytinder, Cylinde r Head
B.
Crank Shaft, Conn ec tin g Rod, Piston
21
C.
Cam Shaft. Valve, Cam Chain ........ . . •.. . ... . ..... • ..... · .• · ·
24
D.
Uppe r. Under Crank Case
26
........ •• ....... • •.......•.... • • ...
Maintenance Items
Items to be inspec ted, serv ice -wise.
E.
Clutch, Crank Case Caver L/H
Standard Value
This indicates the manufacturer's standard si ze or th e standa rd size
F.
T ransrn ission
aft e r newly as se mbling or adjusting, and shows th e size -limit o f
G.
Gea r Change
comple ted part in the permissible limit of adjustm ent.
H.
Kick , Crank Cas e Cover R/H ...•... . . . . ....... . - ....... - . . . .. .
30
I.
Oil Pump. Oi l Filter .. . ....... . ... .... - ... . ... - . ..... - • • . .... .
30
J.
A.C. Dynamo, Starting Motor .. •• • .....•.......• . ..... . •. . . - . ..
32
K.
Conta ct Br eaker
...... _ ... . .•.. ... . _ . . . . . . . . . . . . . . . . . . . . . . ..
32
...... _ .... . _ •... _ •. .... .. .. ... . .... ..... ... ... . .. . .
33
Repairing Limit
Unusable wear limi t of 'parl s requi ring cor rec ti on o r replacement,
function-wise.
Remarks
Unmarked numbers are run unit a nd inch unit shown underneath,
and othe r s a ccording to the unit indicated.
UNIT IN CHART:
Unmarked numb e rs are m/m unit and inch unit shown underneath,
and othe rs according to the unit ind icat ed.
3.
....
.. .. . . • . .. . .. .. _ ........... . _ . . .
27
...... . .... .. ............... . .... . .......
28
. .....
.........
. .. .. ...... ... . .. ... . 30
FRAME
A
Handle
B.
Front Cushion
33
C.
Steering Stem, Front Fender . ... . .•. ..... ... . . .......... .•. . . .. .
35
D.
Fuel Tank ........ .... .. . . .... ...... . . ....
36
E.
Fra me Body
F.
Stand ............... . ......... . .. . . . .
G.
Rear Fork, Rear Fende r ..
H.
Rear Cushion . . ........ .
I.
front Wheel
38
J.
Rea r Wheel
39
K.
Electric Equipment ..... .. .
.
... . . . . • . . - . . ... . . .... .
. ... . .. ..... .
. . ... . . . ...... . .. . 36
37
.
..... .. .. . . . ...
..
.. . . . .
. . ...
. ... .......
17
,
37
. ... ... . .......... . 38
... . . . . ... ... . .... . .
40
"
MAINTENANCE STANDARDS (Model C872, C877)
In this lis t, the d imensions without uni ts indicate "m m" (u pper step) and "inch" (d own slepl,
and ot hers acco rding
the
10
units
indicat ed.
Mark
*
is
exc lusive ly used on ly for
model CB77 and oth er s are commOn both model CB72 and CB7l.
1.
GENERAL PERFORMANCE
I Ie m
I Repoicing limH I Adi",HngPo int
Standard
10.5 kg / em'
14 9.34 Ib/ in'
45 km/
127 Br m.p.g.
9.3 - 9.7
C om pre ss ion pressure
e
Fuel Consumption
C om pre ssi on ral io
l ub ricating oil con-
120 ee / l 000 km
less
120 ee / 0.62 mile
sumpli o n
8.0kg/ em less Disassemb le
113.78 Ib/ in' and adiust
26km/ less Disassem ble
73 Br mpg
a nd adj ust
ou l standard
Disasse mble
and adjust
200ee/
Disossembie
e
1000km more
Remarks
Measure with kick
Speed 40km / h
124 8 m.p.h.l
and adiust
200ee/
0.62 mile
l ub rica ti ng oil. capo -
oul sta ndard
1500 ee
Adjust
city
gouge
16PS morc
18PS more
0
62
0
85
RC:Jr wheel output
*
Caster
Trai l
2.
A.
Ch eck with oil
12 .5PS less
14PS less
Disassem b le
Oul standard
Exchange
(Refe rential val uel
out standard
Exch an ge
(Refe r en tia l value I
Sl o!1d ord
Repoiring limit
Adjust in g Point
w it hin 0.01
0.05 more
Put in boring
(Max . output!
and adjust
ENGINE
.cylinder, Cylinder Head
'"
"<'~
It
C ylinde r sleeve
Cylinder sleeve
e m
Differ ence
betw ee n
. ::. ~m ax. in. d ia .
. 'a nd min. i n.
dia.
In. dia.
enforced
.
54.00 - 54.0 1
:!~;~S, 2.1259 -2.1263
54 .10 mor e
2.1 29
'~~ . '
C ylinder barrel
Heig ht
C yl i nde r sleeve
Out. dia.
Put in bori ng
After bo ring, hon ing shou ld be
enforced
-;.;. : .
...
After baring, honing should be
0.00196
0.0003
Remarks
*
60.00 - 60.0 1
2.3622 - 2.3625
1
83.45-93.5
. ·3.285 - 3.681
f60,lO more
2.366
aut standard
r
.- '::0 '.02 - 62.03
::;:1:2:441 - 2.442
* :c"t7.02-67 .03
2.638 - 2.6387
19
,
(Referential valuel
,"
B.
• lie m
Cylind er sleeve
I
Inlaying
space
Cylinder
Over size
(oversize)
Cylind e r head
In. dio.
(Cam shaft bearing
part)
Cylinder hea d
(rocker orm pi n)
Remarks
0.02-0.05
0.00078 - 0.001%
Be pr essed in at
the normal tern·
pe rature
It e m
0.25
0.0098
41.994-42.01
1.653 -1 .654
Bor ing
Cron k sha ft camp.
Ex change
Sprocket, center
1.655
In. dio.
Comb ustio n
17.0-17.018
0.669 - 0.670
29.3 - 29.7 cc
17.05 mo re
Bend
Cylinde r head
(head cove r attach.
ing facel
Bend
Cylinder head
Unl e t po rn
In. dio.
Carburettor in su lat o r
Gop of the
in. dio. of
inlet porI
Width
In. d io. of
Bush
Tachometer gea r
Out. d ir. o f
Bush
Tach om~ !er ge ar
Tight nes s
"0" ri ng, 14m/ m
Tach ome ter gear
Clearance
and bush
Cyli nder head cave r
Br eathe r sield plate
Flalneess
Thickn ass
Breather sield plote
Attaching
dire ction
Cylinder head cove r
Tighting
torq ue
Cylinder head co p
Tighti ng
Cylinder head cap
Dio.
torque
"0" rin g
0
360
0
Rema rks
16
36 .285 - 36.286
1.428 - 1.428
22
0.671
!Referenlial value}
Gear, center crank
No. of tooth
shaft sprocket
0.03 less
0.00 1
0.03 less
0.001
0.06 mo re
Thick ness of
crossove r
teeth
15.295 -1 5.337
0 .602 -0.603
15.1 less
0.59 4
Ex ch an ge
Rectify
Rectify
Oul. dia.
47 .9 -48.0
1.885 - 1.889
38.003 - 38.0 15
1.496 - 1.496
0.006 - 0.0 14
47.7 less
1.877
38.05 mor e
1.498
Exchange
0.05 more
Ex change
25.991-25 .999
1.023 - 1.023
25 .0 -25.02
0.984 - 0.985
25.907 - 25 .291
1.019-0.995
29.983-29.993
1.1 80-1.180
0.03 less
0.001
4.0 - 4.03
0.157-0.158
4.0 -4.1
0.157-0. 16 1
be pr ocessed
25.95 less
1.021
0.0040 I
Ex chang e
29.95 less
1.179
Exchange
0.1 mo re
Rectify
0.002
0.06 more
0.002
Out. dia.
Cylinde r heod gaske t Width
Toch om eter gea r
III BI
Tooth
Bottom dia.
Exc hange
chamber
!a tt aching face}
Cylinder pock ing
180
Adjusting Poin t
" BI
3 cat ego ry of 0.25
capacity
Cylinder he ad
Crank angle
Crank angle
42 .06 more
Repa irin g limit
Standard
cronk shaft
(rocker orm pi n)
C ylinder head
Standard
Crank Shaft, Connecting Rod, Piston
25.5
1.003
0.5 less
0.0196
Radial
1.0 mo re
Rectify
0.028 - 0.043
0.00 I - 0.00 I
0.03 less
0.001
1.0
0.0393
Center cronk wei ght
Cent er cronk
When tighting
Oul. dia. of
pi n
When I~hling
shaft,
In. dia .
pressed port
In. d ia.
R. crank shafl,
7.2 more
bearing port
Exchange
Oul. dio.
R. crank shaft
0.283
bearing part
Crank shaft camp.
Unless o mi s!.ion,
there are no
troubles
0.2 more
Exc hang e
0.0078
0.0 6 more
R,
Cro nk shoft
key
Max. swing
Width
groove
U nless omission,
th e re are no
troubles
Thick ness
Length
Rect ify
l. cronk shaft pin,
In . dia.
pressed po rt
l. cro nk shaft
put forward
an a rrow
Be ca refu l of the
mark
1.9 - 2.3 m-kg
1.9m-kg less
13.73 -16 .62 ft/ eb 13.73 ftl b
0.45 m- kg
0.35m-kg less
3.25 ftl
b
b
3.2
0.125
0.0984
Rectify
e
2~35 flt~s~
Re ctify
O ut. dia.
pre ssed port
*
8 spots are equal
Primary drive sprocket
No. of tooth
Measuring
I
Ex change
bo ttom dia.
25.907 1.019 30002 1.1 81 30.004 1.1 81 15
25.921
1.020
30.0 15
1. 187
30.009
1.18 1
39. 11-39.21
1.539 - 1.543
21
20
Exchange
.
.'
{Re fe ren tial value!
0.003
4.10 more
0.161
Re ctify
or
exchange
(Referential value!
{Referen tial valuel
with one culle r
0.002
e
teeth 3
clea ran ce
0.039
1. 0-1. 1
0.039 - 0.043
0.3-0.4
0.0118-0.0157
7.0-7.015
0.275 - 0.276
13.982-14.0
0.550-0.551
0.4
0.015
No. of crossover
•
25.95 less
1.021
29.97 less
1.179
Excha nge
38.9 less
1.531
Exchange
.'
'I t e m
Oil nlfer drive
I Repo; ,;og Um;t I Adjust;og Po;ot I
Standard
I
No. of tooth
It e m
Pist on ring g roove
!
24
width
Groove
Piston ring groove
25.0 - 25.01
0.984 - 0.984
45.15 - 45 .3 48
1.777 - 1.785
15.0 16 ~ 15.043
0.591 - 0.592
without 0.02
0 .0007
17.97 -1 8.03
0.707 - 0.709
3 1.005 - 31.015
1.220 -1 .221
0.07 -0.33
0.002 - 0.012
0 - 0008
0 - 0.0003
2.502 - 2.51
0.0985 - 0.0988
13.45 -1 3.5
In. d io.
Mea su ri ng
bo tt om dio.
Con necting rod small
In. dia.
end
Twist
.ad big
Thickness
end
In . dio.
Axial
cleara nce
Diag o nal
cleara nce
Needle ro lle r
Oul. dio.
Le ngth
I
26.0 mor e
I
Exchange
I
1.023
45.05 less
1.773
Exchange
15.1 mor e
Exchange
0.594
0. 1 more
Exch ange
0.0039
17.5 less
0.688
31.04 mo re
1.222
0.5 more
Piston ring g roove
t
width
Piston ring g roove
Exchange
Exchange
Out. dia.
*
!
Piston & cylinde r
t
Exchange
clea ra nce
Piston ove rsize
Ove rsize
Pi ston ring
Wid th
•
Exc hange
,,
Pi ston rin g
ISecondl
I
T hickness
Out. dio.
Overall
length
•
Piston head
Oio.
•
Piston skirt
Die.
•
Piston
Ta per
14.994 -15.0
0.590 - 0.5905
45 .9 -46.1
1.807 - 1.814
5 1.9 - 52.1
2.043-2.05 1
53.65 - 53.7
2.112-2.114
59.65 -5 9.7
2.348 - 2.356
53.98 - 54.0
2.125 -2. 126
59.98-60.0
2.361 - 2.362
First step
I
14.95 less
0.5 88
Ten sion
(Referential value)
53.6 less
2.1 10
* 59.6 less
2.346
53.9 less
2.122
59.9 less
2.358
out -sta nd ard
•
Exchange
Width
Piston ring
(Seco nd I
Exchange
Th ickness
,
Exchange
At the pin boss
I
Excha nge
Ten sion
I
Exchange
,
End gop
pin boss diagonal
direction
oul-standa rd
Exchange
Measu re at 5 m/ m
uppe r point from
the foo t of ski rt
II
Exchange
Exchan ge
• 53.1 less
2.090
0.06 mo re
0.0023
Exchange
1.4 le ss
0 .0551
•
•
•
I
0.62-0.82 kg I
1.366 -1 .807Ib,
0.7 ~ 1.0 kg •
1.54 3 - 2.204Ibs
0.15-0.35
0.0059-0.013
0.2-0.4
'"
,
0.0078 - 0.0 157
1.48 -1.495
0.0582-00588
I
2.4-2.6
0.0944 - 0. 102
2.6 - 2.8
*
0.0944-0. 110
0.6-0.8kg
1.322 -1 .763Ibs
0.7 -1.0 kg •
1.543
! 2.2041bs
I
0.15 - 0.35
0.0059- 0.0 13 I
• 0.2 - 0.4
*
0.0078-0.0157
I
I.
I
I
23
22
0.0116
47.9 less
1.885
•
I
Measure at the
0.14
0.005
0.16
0.006
2.95 more
I
diag onal direction
Exchange
0.061
•
Second step
El lipse
, End gop
Remarks
0.06 1
Exchange
1.45-1.46
0.057 - 0.057 4
1.45-1.465
0.057 - 0.0576
2.4-2.6
0.0944 - 0.1 02
2.6·- 2.8
0.0944 -0.1 10
t
Exchange
1.55 more
•
Excha nge
D- 0.06-0 07
D-0.002 - 0.002
D- 0.12 D-0004 0.14 0.005 -
I
*
ITop l
Pi ston pin
I
I
Pi sto n ring
1.55 more
0.25
0.0098
ITopl
0.0019
2.5 less
0.098
1.893 - 1.897
53.3-53.4
2.098 - 2. 102
Min.
~
0.529 - 0.53 1
48 pes
No. reqd.
Groove
10ili
0.0196
0.05 more
width
ISecondl
I Repo;,;ng UmH I Adjusting Foint
Standard
1.505 -1.52
0.0593-0.0598
1.505- 1.52
0.0593 - 0.0598
2.805-2.82
0.0 11-0.01 11
48. 1-48.2
Groove
ITo pi
sprocket
Connecting
I
Remarks
1.4 less
3 cotegory of 0.25
10.00981 oversize
Exchange
I Exchange
0.0551
2.2 less
0.0866
Exchange
2.4 less
Exchange
0.0944
I
0.5 kg less
1.I021bs
0.6 kg less
1.322 Ibs
Exchange
Tangential tension
Exchange
0.6 mo re
Re ctify the
0.023
When attaching
nar row ring
Exchange th€
0.65 more
0.0255
1.43 less
I
0.0562
,
2.2 less
I
,
0.0866
2.4 less
0.0944
0.5 kg less
1.1 02 Ibs
0.6 kg less
1.322 Ibs
wide ring
Exchange
Exchange
Exchange
Ex change
Tangential tensi on
Exchange
Rectify the
0.6 more
0.023
narrow ri ng
0.65 more
Exchang e the
0.0255
wide ring
I
When attaching
'I t e m
I
Width
Piston ring
10ili
Thickness
Tension
End gap
I Repei,i'9 limit
Standard
2.4 - 2.6
0.0944 - 0.1 02
* 2.78 - 2.795
0.109 -0.110
2.78-2.795
0.109 - 0.110
* 2.6-2.8
0.0944 - 0.110
0.7 - 0.9 kg
1.543- 1.984105
* 0.9 -1.15 kg
1.984-2.53Ibs
0.1-0.3
0.00393 - 0.0118
2.0 less
10.07871
I
Adjos';'9 Poiot
I t em
Remarks
Type
Com chain
Ex change
I
Length
Exchange
*
.
2.7 less
0.106
2.5 less
0.0984
0.5 kg less
1.1021bs
0.7 kg less
1.5431bs
Exhaust valve
Thickness
Exhaust valve (Steml
Out. dia.
Exhaust valve
Angle
Exchar,ge
Ex change
Ex ch ange
Tangential tension
Thickness
Wh en a ttaching
Rec tify the
0.0314
Overall
length
~
Inlet valve
0.8 more
narrow ri ng
Inlet valve ISteml
Out. dia.
Exchange the
wide ring
Pisto n ring & groove
0.045 - 007
Clearan ce
0.15 more
ITopl
Piston ri ng & groove
0.04-0.07
Clearan ce
0.01-0.0 4
Clearance
0.0 1- 004
i<
0.15 more
*
0.0059
ISeatl
Inlet valve
Exchange
Valve spring flnn er!
3 category of
0 .25 ove rsize
Valve spri ng tOuler!
Cam Shaft Valve Cam Chain
1t e m
Com shaft
lBearing partl
I
I
Out. dia.
Height
Cam (Bearing parl l
Cam sprocke,t
complete
I
19.996 - 20.009
0.787 -0.787
In 31.67-31.71
1.246 - 1.248
Ex.30.54 - 30.58
1.202 - 1.203
,
In
5.69
,
0.118
Ex.
4.56
0.179
32
I
,
Com shaft
I Repei,i '9 limit
Standard
lift
Nos. of
Ad iu5fing poi :"! 1
I
DK- 219
723.0 - 723.8
28.464 - 28.496
1.0
0.0393
6.96-6.97
0.274 - 0.274
90-91 0
728.0
28.661 more
0.5 less
I
0.00196
,
6.94 less
0.273
Exchange
OUI-slanda rd
Exchange
88.7 4 - 88.7 6
3.493 - 3.494
1. 0
0.039
6.98-6.99
0.274 - 0.275
90 0 -9 10
89.4 leSs
3.519
0.5 less
0.019
6.96 less
0.274
I
I
Max. lift
Exhaust valve guide
In . dia.
Inlet val ve guide
In. dia.
Valve seat
Touch width
Rocker
o,m
In. dia.
I
Exchange
89.96-89.98
3.541 -3.542
37.5 4
1.477
0.8 less
1
7.6 - 8.4 kg
18.9 -20' kg
16.754-18.518
41.667 - 44.31 3
43.36
1. 707
0.8 less
degree
Tension
,,
74.2 less
2.921
24
Remarks
Exc honge
I
74.766
2.943
I
Free length
Diagonal
Exchange
,
teeth
Bottom dia ,
19.95 less
0.785
31.4
1.236
30.2 less
1.188
Remarks
Rectjfy or
Exchange
I
out-standa rd
Exchange
Exchange
Ex change
I
I
or rectify
Ex cha nge
II
89.6 less
3.521
36.0 less
1.417
Ex change
1.5 more
Exchange
60 kg less
16.0 kg less
13.227
35.273
42.0 less
1.653
Ex chan ge
Ex change
d egree
Tension
0.25
0.00984
O versize
Free length
Diagonal
Exchange
0.00393
Piston ri ng oversize
Overall
Exchange
0.1 more
10ili
Angle
lenglh
0.00393
Piston ring & groove
I
Exc hange
0.1 more
(Second I
C.
Inl et valv e
0.0059
*
I Repeid'9 l imi t Adjusti'9 poiot
ISeat facel
Exhaust valve
Exchange
I
Standard
Rocker arm shaft
tRacke r orm partl
Out. die.
I
I
I
,
I
i
Excha nge
1.5 more
Exchange
15.0 kg less
Exchange
1
16.9- 18. 1 kg
34.4 - 34.6 kg 32.0 kg less I
37.257 -29.9 03Ib, 33.0691bs le"l
7 5.838-7 6.279Ib, 70.547 Ibs less'
7.0 -7.0 1
7.05 more
0.275 - 0.2759
0.2775
7.0-701
7.05 more
0.275 - 0.2759
0.2775
I
1.0
20 more
!
0.039
0.08
13.0 -1 3.027
13.1 more
0.51 1- 0 .512
0.515
12.966 -1 2.984
12.9 less
0.510 - 0.51 1
0.507
I
25
Exchange
Ex chang e
Rectify
Repair of cy linder
head
Ex change
Ex change
I
'I t e m
shaft
IInloy port of heodl
Rocker arm
Rocker arm shaft
I
16.994-16.976
0.669 - 0.668
2.5
0.0984
0.08-0.12
0.003 - 0.047
40
1.574
Out. dio.
In. dio .
10il partl
T oppe l clea ran ce
In. Ex.
Out. dia.
Cam chain
IRepaidng limit I Adjusting point
Standard
tensioner roller
16.95 less
0.667
L/ H cover attac hing
Ex change
case
Com chain guide
out-standard
roller (Spring)
Tension
Valve timing ex.
Opening
38 less
1.496
angle
dead point
Closing
dead point
Opening
Cold type
Rectify
10 °
angle
!
dead paint
5°
angle
dead point
30 °
Oil level gauge
Exchange
Referential value-
all length
Check at 1.1 m/ m
Rectify
Un case of liftl
Check at 1.1 m/ m
Rectify
(In case of lift)
Check at 1.1 m/ m
Re cti fy
lin case of liftl
Check at 1.1 m/ m
Rect ify
+5°
,
Upper · under cronk
I
In. dia.
case lPart of center
IRepairing limit I AdjuSiing point I
Standa rd
66.04 more
l/H76.97 -76.987
R/ H64.97 -64.987
3.0307 - 3.0309
2.557 - 2.558
61.985-61.996
2.440 - 2.4407
76.93 more
Exchange
In. dio.
case IPart of bear-
ing l/H, R/ HI
Upper' under~lcronk
lPart
In. dia.
of mis-
Exchange
i Slip
oul of
3.0287
2.556
62.04 more
2.442
It e m
I
Thickness
I
In. dia.
of kick
25.0 - 25.021
0.984 - 0.985
25.1 more
I In . dia.
Flatness
Clutch plate
Thicknes s
Combined with
flotness
upper and under
spindle)
Upper' under cronk
I
within 0.03
0.06 more
0.002
Flatness
0.001
within 0.03
0.06 more
face of upper cronk
0.001
0.002
case
26
I Combined with
I Out.
upper and unde r
Rec tify
Flatness
case (Seam surface l
Cylinder attaching
Excha nge
0.988
a nd then measure
Clutch center
clutch plote
and
Clutch cente r
mission shaft
and
Rect ify
Rectify
,
Exchange
I
Exchange
I
Exchan ge
0.0019
0.06 more
Re ctify
0.002
0.06 more
0.0012
0.0023
Rectify
I
0.1 more
Rectify
0.0039
dio.
: Repairing limit Adjusting point
2.5 less
0.984
Excha nge
within 0.2
0.4 more
Exchange
0.0078
2.0
0.078
0.015
1. 6 less
0.0629
Exchange
within 0.2
0.4 more
Exchange or
0.0078
0.015
Repa iring
I
Remark s
One set is 6
sheets
Use 5 sheets
135
5.314
C learance
of rotary
direction
Clearan ce
of ro tary
direction
I
Standard
2.9-3.0
0.114-1.18 1
112
4.409
I
Exchange
0.5 less
not remain
i
Exchange
Clutch. Crank Case Caver L/ H
Remarks
and th en measure
and crack
of rubber should
0.555
13.9 less
0.547
2.8 less
0.110
within 0.03
0.00019
upper and under
,
Aging
Exchange
14.1 more
I
Remarks
Rectify
58.0 less
2.28
within 0.05
I
I L/H or R/ H
seam surface
and then measure
Upper ' under crank
(Part
Under cronk case
Combined with
64.93 mo re
sian shaftl
case
Flatness
and then measure
Upper' under crank
I
upper · under!
upper and unde r
bearing)
Flatness
(Seam su rface of
Combined with
2.60
0.002
Adjusting point
caver L/ H
Under crank case
Clufch friction disc
65.97 -65.987
2.597 - 2.598
Dia.
attaching face of
E.
Upper ' Under Crank Case
It e m
case
Un case of lift)
0.06 more
0.001
0.55 1- 0.5518
13.966 - 13.984
0.549 - 0.550
2.9-3.1
0.114- 1.22
2.0
0.078
within 0.03
0.001
I Out. dia.
T ightness
Und e r cronk case
within 0.03
14 .0-14.018
"0" ri ng 22mm
control by ove r
IRepai ring limit
I
In. dia.
I
Com chain guide
Standard
59.5
2.342
roller pin
+5°
out-standa rd
Out. dia.
!
of rubber should
Ex change
±5°
ou t-standard
after lower
I
I
roller
Aging and crock
Excha nge
±5°
out-standa rd
before upper
Closing
D.
35 °
after uppe r
angle
Valve timing In .
out-standa rd
before lower
I Flatn ess
I
60.0 less
2.362
5.5 kg less
12.1251bs
63.3
2.492
7 kg
15.4 32 1bs
Free length
I
face of upper cronk
nof be.
Com chain tensioner
It e m
Remarks
wirhin 0.3
0.3 more
0.0118
with in 0.1
I
Excha nge
0.0118
0.3 more
0.0039
0.0118
I
27
Clearance at out.
dia. of plate
Exchange
-'
I
Ite m
Repa;r;'g L;m;'
Standard
, t e m
Adj usti ng po int
Mai n shaft and M 3
C1ulch oute r compo
Teeth
47
11.851
136. 15 - 136.16
5 .360 - 5.3606
135.5 less
5.334
Excha nge
Measure bottom
die.
(
Axial
and
mission shaft
I
clearance
Flat ness
Cl utch pressure pla te
In. die.
spring
I
Free length
Diagonal
,I
I
Cronk case cove r
degree
Load
Flatness
L/ H
Cronk case cove r L/ H In. die.
IParl of oil fllted
Cronk cese cover
Tightne ss
L/H I" 0" ringl
Cronk case cave r
L/H lParl of sh ifl
In. die .
88.0 3.464 0.027 0.001 -
88 .035
3.465
0.067
0.0026
Mission gear
Top
Top
0.2 more
Exchange
0.0078 more
within 0.1
0.3 more
0.0039
0.0118
'112 14.4091
33.4
32.4 less
1.314
1.275
1.0 less
2.0 more
0.0393
0.0787
15.3 -1 5.7 kg
13.6 kg less
33.73 - 34.6 1I bs 29 .982 1bs
wi thin 0.0 1
0.06 mo re
0.0003
58.0-58.046
2.283 - 2.285
0.0023
Top
Exchange
In.
gear
Top
gea r
gear
{Bushl
bush and
Ex ch ang e
BO ll om dia.
Drive sprocket
Clea rance
Counter shaft
Exchange
In. dia.
(gea r sidel
Coun te r shaft
O ut. dia.
Bush
In. d ia .
Rec tify
14 mm
Out. dia.
0.5 mo re
0.0197
14.0 - 14.018
0.55 1- 0.5518
out· standard
Exchange
14.1 more
Exc hang e
C ounter shaft
and
C~ gear
sha fl
Out. d ia.
Mai n
shaft and M,
C learance
gear
Main shaft
0.03 - 0.078
0.0012 - 0.00307
0.1 more
Rema rks
0.089 - 0. 178
0.0035 - 0.0070
18 .0 -18.018
0.708 - 0.709
8.0 - 8.0 15
0.3 14- 0.3 15
20.5 - 20.521
0.807 - 0.8079
0.08 1
0.00318
65.649 - 65.776
2.584 - 2.589
0.03 - 0.078
0.001 18 - 0.00307
24.37 - 24.385
0.959 - 0.960
24 .96 - 24.939
0.982 - 0.981
14.375 -14. 393
0.565 - 0.566
24.98 - 25.013
0.983 - 0.984
0.0 1- 0.098
0.00039 - 0.0038
0.2 more
Exchange
0.0039
gear
C rossover
When disassembly
thickness
and mainten ance,
Kick storto r spindle
exchange should
and bush 14 mm
Bush C 14 mm
Axial
Clearance
Clea ra nce
O ut. d ia.
In. dia.
IRepa;r;,g L;m;' IAd juSI ;,g po;"
Mission gear
Re marks
Fi rs t
24.9 less
0.980
Excha nge
0.1 more
Excha nge
0.0039
1.2 more
18.2 more
Exchange
0.7 16
8.06 mo r e
Exc hange
0.3 17
20.6 mo re
Exchange
0.811
0 .1 more
Exchange
0.0039
64.7 less
2.547
Exchange
0.25 more
Exchange
0.0984
24.4 more
Exchange
0.9606
24. 9 less
0.980
Exchange
15.2 more
Exchange
0.598
Exchange
0.2 more
Exchange
0.0078
2 1.667 - 2l.71 4
0.853 - 0.85 4
0.022 - 0.052
0.0087 - O. 0020 4
17.09 4-17.112
0. 672-0.673
14.413-14.4 31
0.567 - 0.568
3. 12
21.61ess
0.850
0.15 mo re
0.0059
17.05 less
0.67 1
14.53 ma re
0.572
Exchange
Exchange
Exchange
Exchange
gea r rotio
2nd
1.7 4
3rd
l.27
To p
l.00
Four sp eed
24.959 - 24 .98
0.968 - 0.983
0.02 - 0.074
0 .007 - 0.0029 1
0.1- 0.75
0.0039 - 0.0295
Exch a nge
0.0078
di r ect ion
Constant mesh gear
Main
Cleara nce
of ro ta ry
0.555
0.3 - 0.4
Standard
Type
Clearance
Dri ve sprocket
Transmission
T ro nsmission
dia.
{Rotary direction l
be done each time·
I
In.
Exc hange
0.01 18-0.0157
m
dia.
missi on shaft
L/H IPackingl
" e
dia.
(lifter rod partl
Low
Thickness
In.
gea r
Refe rential value
spindle)
Crank case cove r
Bock rush
rolle r dio.
0.35
In . die.
F.
Ad ju sting point
direction
Bottom die .
C1ulch
Clearance
of ro tary
gear
(with sprocket)
Clut ch center
IRepa;r;,g Lim;'
Standa rd
Remar,ks
Kick spindle
sp ri ng
Exchange
pole
Free
le ngl h
14
0.551
13.5 less
0.531
0.0472
29
28
•
Exchange
lParl of 20.5911
1
t e m
Kick spindle pole
I
Out. dio.
bush pi n
Overall
length
Primary chain
Roller
Deflection
5 X 6.25
G.
No. Reqd.
I
I Repc""9 UmH I Adjusti'9 poi", I
Standa rd
I
Exchange
Oil pump gea r side
Exchange
Clearance
face and side cover
Show by max.
Exchange
swing of loosing
Oil pump gea r and
Clearance
pin
Oil nlle r shaft a,d
Clea rance
oil filte r rotor
Oil filter rotor
Out. dio.
Oil nller cha in
Loosing
Gear Change
It e m
Gear shift fork
Gear shift drum
Drum and shift fork
Gear change pedal
I
In. dio.
I Repo iri'9 UmH i Adj ustin 9 poi", I
Standard
34.2 more
1.346
33.9 less
1.334
0.25 more
0.0098
17.3 mo re
34.0 - 34.025
1.338-1.339
33.95 - 33.975
1.336 -1 .337
0.025-0075
0.0098 - 0.0295
17.0 - 17.027
0.669 - 0.670
Out. dio.
Clearan ce
In. dio.
I
Standard
Repai"'9 Umit AdjusH'9 poi,t
0. 106-0.21
0.004 17 -0.0082
0.04-0.089
0.0015 - 0.0035
0.0 13 - 0.05
0.005 11- 0.000 19
0.0 12 - 0.048
1
0.00472-0.00188
57
2.244
5-10
0. 196-3.937
Back rush
Oil pump gea r
4.5 less
0. 177
12.5 less
0.492
20 mo re
0.7874
5
0.196
13
0.511
5 - 10
0.196 - 0.393
12 pieces
It e m
Rema rks
Remarks
0.4 more
Exchange
0.0 15
0.1 more
0.0039
Exchange
0.3 more
Exchange
0.00 118
0. 1 mo re
0.0039
Exchange
15 more
5 .905
I
I Exc hange
Remorks
Measure the omplitude at the center
.
Exchange
J.
A. C Dynamo Starting Motor
Ex change
l ie m
I
Exchan ge
Spark pe rformance
on ignition
Exchang e
3 Needle
gap
Charg ing perfo rmance Charging
0.709
on dynamo
IRepo i';'9 limit iAdjusti'9 po i", I
Standard
B mo re 300 r.p.m.
0.3 14
2.0-3.0A
Remarks
7 less
0.275
Exchange
3 Needle gap
out-standard
Exchange
start of charging,
current
at
1700 r.p.m.,
afte r thot, at
H.
Kick, Cronk Case Cover R/ H
r I e m
Kick starto r gear
I
Clearance
,
and coWr R/ H
Cover Rt J\l.
Flatness
~;...
.'.
I.
I Repoi ,i'9 limit I AdjuSli'9 poi,! I
Standard
14.34 1 - 14.353 I
0.564 - 0.565
0.016 - 0.104
0.00063-0.0409
Shaft Out.
dia .
Kick startor gear
500 r.p.m.
14.25 less
0.561
I
Dynamo starter and
Remarks
rotor
Starl ing clutch oute r
Exchange
and dynamo
Cross screw 6 X 24
0.3 more
Clearance
Excha nge
Ou t. dio.
gap
Tighting
to rque
within 0.05
0.1 more
0.000196
0.0039
I
Clutch roller spring
Free length
Cl utch rolle r spri ng
In. dio.
exchange
Oul. dio.
Oil pump drive gear
T eeth width
Bend
Oil pump drive gear
Bock rush
and M. cronk gea r
Oil pump gear top
and inside wall
Clearance
I Repoiri'9 limit : Adjusti'9 poi",
Standard
,
4
0. 157
0.05
,I
0.00019
0.085 - 0. 127
0.00334-0.050
0.025 - 0.05
0.0098 - 0.0019
Remarks
Storting sprocket of
I
Starting motor
0.1 mo re
0.00393
,
24 less
0.944
Exchange
I
1
4.3 more
Exchange
0. 169
5.0 less
0.196
37. 1 less
1.460
Exchange
I
Exchange
I
I
I
H orse power
0.4 KW
out-standard
Exchange
I
Roting
30 sec
out-standard
Exchange
I
Adiust by packing
I Exchange
I
When lighting,
I
Rectify
0.15 more
0.1 more
Voltage
25 - 31
0.984 - 1.220
4.1 - 4.25
0. 161 - 0.167
5.2 - 5.3
0.2047 - 0.2086
37.175 - 37.2
1.463 -1 .464
12 V
I
31
30
Rectify
oUI-standard
Exchange
0.00393
0.059
Out. dio.
clutch outer jou rnal
I
I
0.0314
0. 1 more
0.0039
I
Rectify or
ICa p l
I
Ex ch ange
0.8 more
0.01 18
Oil Pump, Oil Filter
It em
0.5
0.0 197
0-0.06
0-0.00236
0.5 m- kg
3.615 ftl lb
screw rod should
be needed.
,
K.
J
Contact bre ake r
I I e m
Contac t pOint
Max. gap
Ignition timing
Cronk angle
Standa rd
Repairing l imit
0.35
0.01377
out · standard
Repairing
3" Jess
Repai rin g
befo re uppe r
R.P.M.
R.P .M.
r
Remarks
Repairing l :m il
Adjusting pOint
Remarks
out-standard
Rectify
1291
Powe r jet
~ 160
Power air jet
#
mo re
ouf-standard
Exc hange
out .standard
Exchange
37 " _ 43 "
Exchange
3.
90
Cronk angle
40"
advanced max.
FRAME BLOCK
A.
Handle
out - range
I t e m
advanced angle
Carbur e tto r
Standard
Play
Circumference
L.
Adjusting point
2.591
2.091
Pilot outlet
3300 r.p.m.145 "1
advanced finish
Spark advancer
Valve seat
Co rbu retto r
Repairing Limit
1100 r.p.m. 15"1
advanced beginning
Spa rk advancer
Remarks
*
dead pOint
5"
Spark advancer
Adjusting point
Standard
I e m
4-B
Measure at out
0.157-0.314
direction of throttl e
circumference
grip
I t e m
Corburettor
Standard
Type
PW22H
*
Main iet
*
Air ie!
*
~ 2
Difference between
Length
55
2.165
out-standard
133
out ·st andard
Rectify
or
exchange
IhrOllle wire
Length
between outer &
5 .236
Rectify or
exchange
inner
Brake lever
Play
Clutch lever
Play
Front
fork cover
Thickness
cushion
l Out. dia.
2.691
22402-2 step
* 24231-3 step
# 3 wid th 1.2
cutting depth 0.5
*
Remarks
Clutch wire diffe rence
AB2
0.791 X 2
OB¢ X 2
AB3
0.791 X 4
0.791 X 2
*
Cutter way
A4a
ABI
1.091 x2
I. B¢ X 4
*
Needle iet
L
Adj usting point
outer and inner of
PW26
# 100
~ 135
~ 150
Air bleed
Jet needle
R
Repairing Limit
nothing
B.
25 - 30
0.9B4 -1 .417
15-25
0.590-0 .984
6.5
0.0255
39
1.535
out·standard
Rectify
out - standard
Rectify
6.0 less
Check by lever
end
Exchan ge
0.0236
Fro n t Cushion
It e m
Front cushion
I Repo;,;o9 LimH I Adi cst io 9 ponH
Standard
Type
Telescope
type
out·standard
Remarks
Rectify or
exchange
I-IV, return
Air screw
*
Slow jet
I J.i
Stroke
return
# 35
Oil capaci ty
10.B¢ X 4 pieces X
2 stepl
Front cushion spring
* # 42
IO.B¢ X 2pieces X
4
length
lOne step)
Free
80
3.149
out·standard
bath of R. and
L. 250 cc
IB5 .5
7.303
out·standard
IBO less
7.0B
Exchange
Reference value
step)
33
32
C19 389 03 2.
Canterbury Public librarY
"
.
I
[ "I e m
Front cushion spring
I
1
Free length
(Two stepl
Overall
length
Availab le
I Repaidng limit I Adjusting point I
Standard
216.5 less
8.523
396.0 less
15.590
221.5
8.720
407.0
16.024
32
Exchange
[ t e m
I
Remarks
Refe rence value
Seal housing & oil
In. dia.
46.0 - 46.039
1.811 - 1.812
0.06-0.3
0.0023 - 0.011
36
1. 417
33.0-33.039
1.299-1.300
37.466 - 37.491
1. 475-1.476
173.8-174.2
6.842-6.858
42
1.654
34.4-34.6
1.354 - 1. 362
seal
Inlaying
Exchange
space
Fork pipe guide
Overall
length
winding
In. dia.
Nos.
(First step)
Available
30
winding
Front fork upper
Nos.
Front fork upper
step)
case of bind
Torque in
case of bind
Overall
winding
374
14.724
24.1 kg
53.13 Ibs
62
C oil out. dio.
Front fork pipe
Bend
camp.
Front fork pipe
Out. dio.
piston
Front fork valve
In. dio.
Front fork pipe
Space
piston valve
between
Reference value
I
!
flat degree
Front fork bottom
In. dia.
case
Out. dia.
Front fork bottom
In. dia.
piece axis part IRI
Front fork bottom
piece axis po rt
In. dio.
(ll
Seal housing bottom
case inlaying space
In. dia.
Out. dia.
ICove r cushion
I Re feren ce
out-standard
Front fork upper
value
In. dio.
Exchange
front fork under
4.5
0.177
25.0-25.5
0.984 -1 .004
within 0.1
0.0039
Reference value
Overa ll
cover
length
front fork under
Out. dio.
COve r (Upper part!
In . dio.
0.15 more
Exchange
The bend of pipe
0.0059
nut, when mode
the plating por t
a fulcrum
37.45-37.475
1.474 -1.4 75
32.98-33.019
1.298 -1.299
0.055 - 0. 109
0.0021 - 0.0042
37.4 less
1.472
33.1 more
1.303
0.02
0.00078
37.5 - 37.539
1.476-1.4779
41.236 - 41.275
1.623 -1.625
15.0-15 043
0.590 - 0.592
20.0-20.52
0.7874":- 0.807
41.3-41.362
1.625 -1 .628
out-standard
34
33.2-33.4
1. 307 - 1.314
175
6.889
54
2.125
38.5
1.515
54.5-54.7
2.145-2.153
55
2.165
38.1-38.3
1.500 - 1.507
Exchange
Fork rib up per cover
Fork rib unde r cave r
In. dio.
Ex change
I
0.0078
c.
Roughness should
Rectify or
Cha nge
41.15
1.620 less
15.1
more 0.594
20.2
more 0.795
4 1.5
more 1. 633
I I e m
Stem
1.482
Steering head stem
I
Chonge
Chonge
Change
I
& bottom cone ! Binding
ra ce
Chonge
I
I
Chonge
out -slonda rd
33.1
more
1.303
out-standard
Exchange
out · standa rd
Exchange
out·standard
Exchange
,,i
out-standard
Exchange
I
out-standard
Exchange
I
I
I
I
I
Steering Stem, Front Fender
be 1.55 more
cha nge
more
Out. dio.
inlaying part
0.2 more
37.65
In. dia.
inlaying part
Remarks
out-standard
inlay ing partl
fo rk pipe
Foot face
Out. dio.
IUpper parll
Nos.
Die. of co il
Overall
length
[Secondary
Height in
Out. dia.
Reference value
IRepairing limit I Adjusting point I
Standard
nut
Steering stem top
cone ra ce inlaying
part
Steering stem front
fork pipe inlaying
part
I
I
I
I Repairing
Standard
Adjusting point
lim it
0.007 - 0.041
0.004 less
Exchange
6.5 - 7.5 m-kg
4699-54.22 ft/lb
25.979-26.0
1.022 -1 .023
5 m-kg less
36.15 ftllb
Rectify
38.25
1.505
Exchange
space
Binding
to rque
I Out.
dia.
In. dio.
38.0-38.062
1.496 - 1.498
more
I
I
35
I
Remarks
·'
F.
•
Steering
stem bo ll om
I Repoi,;ng Limit
Standard
It e m
Stopper
bridge
ongl e
Steering
In. dio.
76°
out-stan dard
Adjusting point
Rem a rks
It e m
Rectify o r
exchange
(double, side
cone
race
Plank
Front fender
Material
26.0 - 26.02 1
1.023 - 1.024
0.8
0.031
SPC-l
oUI-stand ard
Standa rd
(re ferential va luel
Step arm compo
Step a rm
Exchange
fixing bolt
In. dio.
Out. dio.
Ma in stond pi pe
Thickness
Ma in stand th e hole
In. dio.
of binding par t
Main stond sett ing
Out.
d io.
Free
length
bolt
Main stand setti ng
D.
Fu e l Tank
sp ri ng
Load
fuel
Volume
tonk
Repairing limit
Standard
It e m
14
Adjusting point
Remarks
Exchange
0.499
16.7 less
0.657
Exchange
14.3 mo re
Exc hange
0.562
13.5 less
0.531
83 less
3.26
86.2 kg less
190.0031bs
Exchange
Exchange
Excha nge
In case of binding,
max. streich and
In. dio.
1.2-1.5 e
17.0 - 17.027
0.669 - 0.670
20 - 30
0.787 -1. 18
17.2 more
Ex change
0.677
ou t·stand a rd
Rect ify
Pe po iring limit
Adjusting poin t
Fram e Body
Pepairi ng limit
Standard
r t e m
Ad jus ting point
Rear Fork, Rear Fender
Remarks
r t e m
Head pipe camp.
top boll
ra ce
Bind ing
spa ce
H ead pipe camp .
0.05 1- 0.0575
0.002 - 0.0022
0.001 - 0.05 1
ou t·sta nda rd
out·standard
Steel boll top
dia.
No. Reqd.
Rea r fo rk pivot
In. dia.
Rear fork pivo t bush
Out. dia .
Rectify or
exchange
Out.
boll
Standard
y.("
0.009
18 pes
out ·s tanda rd
Rectify o r
In. d ia .
exchange
boll
bottom
No. Reqd.
19 pes
out·standa rd
Rec tify or
Pr essed
exchange
Rea r fork cente r
In. dia.
bush
Binding
space
14.0 1 - 14.02
0.551-0.551
0.03 - 008
0.001 - 0.003
14.1 mare
0.555
Excha nge
space
Rear fork pi vo t bolt
O ut. d ia.
Overal l
D ri ve cha in
36
__Rema rks
Re ctify o r
exchange
bOll om ra ce
Steel
12.2
0.480
16.957 - 16.984
0.667 - 0.668
2.3
0.090
14.0-14 .027
0.551 - 0.552
13.9- 13.968
0.547-0.549
86
3.385
87.5 kg
192.902Ibs
value I
G.
Stee l
12.7 mo re
Remo rks
load (referent ia l
C learance
E.
Adjusting point
e
Bra ke pedal
Reserve
Pepoiri ng lim it
Measured by jig
+5mml
top
Stand
length
Type
26.0 - 26.02 1
1.023 -1.024
26.04-26.08
1.025 - 1.026
20.05 - 20.08
0.789 - 0.790
0 .0 19 - 0.08
0.0007 - 0.003
13.925 -1 3.968
0.548 - 0.549
301
11.850
OK 530
Teet h
94 tee th
Sla ck
9 -1 3
0.35 4- 0.5 11
37
Exchange
20.5 mo re
0.80 7
Exchang e
Cl ea rance
Exchange
13.8 less
0.543
o ut· stand a rd
Rectify or
excha nge
Afte r pressed in
gi ve a fi nishing
tau ch to the in.
dia.
Sfandard
It e m
Standard
lie m
Pepairing li mit
Adjusting po in t
Rear broke stopper
In. dio.
arm
Thickness
Overa ll
leng Th
H.
10.1-10.2
0.397 - 0.40 I
9
0.354
385
15.157
out-standard
Out. dio.
Exchange
O ve ral l
length
Bend
Exchange
Front wheel rim
Swing
Front tire
Di mension
Rear Cushian
Air pressure
It e m
Ad iusting point
Standard
Pepairing Limit
60
2.362
52 ee
out-standard
Rectify or
out-standa rd
Rectify
Remarks
Front ponel axle
Stroke
Rear cushion
-
Oil capacity
tension
Rear cushion spring
Free length
Load
60 - 67 kg/0.5 m/s
132.27 -147.70
Ibs/0.5 m/s
210
8.267
37.5 kg
82.672 Ibs
In. dia.
# 60
19.9 less
0.783
Exchange
0.2 more
Rectify or
-
0.007
3.0 more
0.118
Front axle distance
Front broke
Overall
eam
Front broke shoe
Front brake lining
Brake drum
Brake shoe spring
Thickness
Out. dia.
Th ickness
In . dia.
Free length
Load
Front axle
Out. dia.
,,
Rectify
15.1 more
0.594
Exchange
Pepairing limit
Adjusting point
4PR
oUI-standard
207 less
8.149
33 kg less
72.7 5 Ibs
Exchange
Standa rd
r tern
Exchange
Final driven sprocket
Bottom dia.
Rear a xle di stance
O ve ral l
In case of 185 mm
(binding height)
collar
Rear wheel axle
length
Out. dia.
15 1.8
,
5.975
100- 100.2
3.937 -3 .944
19.947 - 19.98
0.785-0.786
0.05
150.8 less
5.936
Exchange
out -standard
Exchange
19.8 less ,
0.779
Ex change
0.2 more
Rectify or
Remarks
c,
..
exchange
Standard
length
collar
exchange
Rear Wheel
Overall
tern
excha nge
Rectify or
out-standard
Front Wheel
r
- ..
spindle oil
Bend
I.
19.008 -1 9.96
0.748 - 0.785
238
9.370
0.05
0.00019
1.0
0.0393
2.75- 18
0.108-0.708
1.7 kg/em'
24.179 Ib/in'
15.0 -1 5.018
0.590-0.591
exchange
J.
Declined
Remarks
Adjusting point
Remarks
Front Axle
10.7 more
Pepairing Limit
49.9-50.1
1.964 -1. 972
10
0.393
199.8-200
7.866 -7 .87 4
5
0. 196
199.85 - 200.15
7.868 - 7.879
63.0-63.5
2.480 - 2.499
5 kg
11 .023 Ibs
14.966- 14.984
0.589 - 0.589
Peoa 'ring limit
Ad justing po int
length
Remarks
Rea r broke shoe
Out. dia.
Rear broke lining
Thickness
Rear wheel rim
Swing
Exchange
8 le ss
Exchange
0.314
Shove out. dia.
Rear wheel ti re
2.5 less
0.098
201 more
7.913
66.5 more
2.6 18
3.5 kg less
7.7161bs
14.9 less
0.586
Air pressure
Exchange
Dim ension
Exchange
Rear broke panel
Exchange
Rear brake pane l
Exchange
In case of 67.5mm
(setting length)
Exchange
In.
dia.
In.
dla.
In .
dia.
axle
torque
Bro ke cam
280
11 .023
199 .8 -200
7.866-7.874
5
0.196
1.0
0.0393
2.2 kg/em'
31.2901b/in'
3.00-18
0.118-0.708
20.0 - 20.033
0.787 - 0.788
10. 1-1 0.2
0.397 - 0.40 1
15.0- 15 .Q43
0.590 - 0.592
39
Shove out. dia.
2.5 less
0.0984
Exchange
3.0 more
Rectify or
0.118
exchange
Rectify
4PR
20.1
0.79 1
10.5
0.41
15.3
0.602
Exchange
Exchange
Exchange
.'
K
.
Electric Equlpments
r iead light bulb
Pe p oiring limit
Stand ard
It e m
Electric
Remarks
Adjusting poinl
•
12V
35/30W 2.67 A
DISASSEMBLY AND ASSEMBLY
cu rr ent
Stop lamp
Electric
7.5W 0.58A
In this chapter,
curr ent
Tail lamp
Electric
4W O.28A
moinly Diso ssemb ly
aperotian wos exploined, ond for assembly
speciol attention wos only coi led for where needed, os both operotion are similor.
cur rent
Se renium rectifi rc
Phon
Output volt
DC 30V
Input powe r
AC 40V
95 -1 05 phon
Phon
95 phon less
Adjust o r
Adjust by sc rew
exchange
Fuse
Capacity
Battery
Electrolyte
15A
07
e
out-s tanda rd
Capac ity
10AH
when l A is
charging,
12V
Vol .
Adiust .he
liquid level
copacity
Charge
SlOp switch
1.260 - 1.280
Ma x . a mpe re
PC 2A
1. 18 less
Adiust
Max. a mpe re
Insul a lio n
Resistance
Speedome ter
Erro r
Tachometer
4000 r.p.m.
c
"-
.<:>
'"
~
-<
E
'c"
-2
:"
"u"
~
IM!1 less
O. IM!1 less
Exchange
- 0 + 5%
oul -standa rd
Exchange
±200 r.p.m.
out-standa rd
Rectify or
Exchange
50M!1
10M!1
Exchange
exchange
4000 - 6000
±235
out -standa rd
6000 - 8000
+270
out-standard
Exchange
8000 -
+300
out-standa rd
Exchange
+400
our-standard
Exchange
10000
40
"E0'"
..c
u
~
4A
>-"
0
c
-2
6A
'"
0
~
is
u
~
le ss
10000 12000
!:'
0
u
g
<>.
Ma x. ompe re
E
~
'a"
~
~
<I>
Combination switch
c
0
"
6- 8
Stroke
'"
"-
0
"0E'" 0Ec
>:D c
E
10.6V less
Spec ific
g rav ity of
el ect rolyte
c
g
!:'
<I>
~
o'
~
E
<I>
~
~
a
~
~
a
'"
E
-{..
:"
"u"'"
~
<>.
1-
"0
u
c
0
E
E
0
u
"ac
!:'
'c"
<I>
<9
~
o(l
0
0
I-
DISASSEMBLY AND ASSEMBLY
1.
ENGINE (C72 . 77)
A.
CONTENTS
1.
Disassembly
ENGINE 1C72 · 771
A.
Engine replacement
Engine Replacement (L. side)
Precaution
Assembly
Tools
I.
. . . .•. . . . • . . .. . • . . . . . . ....... ... .. . . . . ....
45
L.
Exhaust pipe jOint
nut
B.
C ylinde r . . ... . . .. . . ...• ... . •. . .. •• • .... .•.. . . • .. . . . • . ..•. . . .
51
C.
L. Cover
56
D.
R. Cove r
60
E.
Mi ssi o n (Crankl . ......•.. . • .... • •..... . .... . • ... . • .. . .. . . . •..
62
F.
Cylinde r Head
64
G.
Oil Pump .....
68
T ighten not 10 leak exhaus! gas.
1 D'Xn socket w r ench
Fig .
2.
l. Exhaust pipe muffler
2.
ENGINE (CB72' 771
14 nX" socket wrench
A.
Engine Rep lacement . ... • •.. . . .• ... . ... ... • .... . . . . .• • .... • . . .
70
B.
Cylinder
76
C.
Engine M ino r Ove rhau l, Assembly
77
17"}{JI
sponner
14'Xn
spanner .
3.
l. step bar
Be cautious of the posi-
tion of serotion in
3.
cese of IItting .
FRAME (CB72' 771
As-
semble with pulling
A.
Rear Fork .. . . . . . • . . . . • • . . . . •. . . ..•• . . . . .• . . . . .. . . . . • . . . . • ..
78
B.
Front Fo rk . .. . . . .. •. ... •.. ..• . .. ..• . . ... . . . . . . .• .. . . ...... "
81
in
position
at
the
punch mark. Ti ghten-
ing torque 2.1 kgm
115ft. Ibl
4.
Gear change pedal
Filling angle. one seralion
foreword
in -
clined from ho rizon -
tal position.
10'%1 spanne r
45
43
Precaution
Tools
Assembly
Disossembly
Disassembiy
Precaution
Tools
Assembly
9.
5.
IR.· sidel
l. frame dust sh ie ld
R. exhaust pipe jOint
nut
Tighten
not
10
leak
Refer to l. side
exhaust gas.
10.
6.
R. exhaust pipe muffler
Plug cop
Re f er to l. side
Ai r vent tube
Fig. 6
11.
7.
R. step bar
Carburelter
setting
Assemble with nuning
Fit securely
in
nut
position
at
Ihe
puncn mark, lightening torque
2.1 kgm 115ft. Ibl
Refer to l. side
Fig. 7
12.
8.
Tig~llening
Breather pipe
2.1 kgm 115ft. Ibl
Engine hanger bolt
Starting motor coble
torque
17 1';:11 socket wrench
Tightening torque
4.4kgm 132ft. Ibl
17"X"
spanner
10% spanr. er
Fig. 9
fi g. 8
47
46
Assemltly
Disassembly
Disassembly
Precaution
Tools
Precaution
Tools
Assembly
17.
13.
Chain jOint clip
Refer to l. sid e
R. dust shield
forehead
T·Handle
driver 1#31
fig. 13
14.
R. crank case cover
T-Handle
forehead
i'
driver 1#31
-----§-
1m; '4;0 _2' ."., Aftk:
TT
!iO'N':B (~ M:taJIl?ii&gI
10 '%1 socket wrench
=
fig. 10
fig. 14
18.
15.
Engine wiring
Clutch wire
Fore driver
f ig. 15
19.
16.
Plug cap
Drive chain joint
Air vent tub e
Dr:ve sprocket cover
Pliers
Refer to L. side
fig . 16
Fig. 12
49
48
B.
Assembly
Disassembly
Cylinder
Precau tio n
Tools
Pr ecaution
Assembly
Disassemb ly
Too!s
20.
Carbu r etfe r
Set le ver of fuel cup
setting
stop.
nul
1.
Condenser
10 '%: spanner
9'%,
socket w re nch
Fig . 17
2.
21.
He ad cove r
En gine hanger bolt
To tighten setting nuls
On
17"%11
Pay a ttention
the head cove r,
follow
o rder
shown
here
10
Ihe
color of nuts.
as
and
repe at 2 10 3 tim es
socket wrench
10
17"XII spo nne r
lighte n securely.
CD@@@~ wh i le
Fig . 18
14"}{1l sock e t wrench
nul
Fig. 21
@@CV@-' yellow nul
3.
22.
Cam ch ain tensioner
Engine setting bolt
14'':n socket wrench
1O"j{1I so cket wrench
Fig. 22
4.
23.
The
pOint of ta king
In case
of
cautious
down engine
age
on
fitting,
be
no t to da mthe
Spark ing plug
Plug socket wrench
frOnl
fender.
Fig. 23
Fig. 19
- .-
51
50
Disassembly
Precaution
Tools
Assembly
Dis a ssembly
Precaution
Toois
Assembly
Combination process
6"}{1I nut
Ci)
steering top COne race
Coincide "T" punch
mark on the dynamo
box wrench
rotor with the arrow
mark On the starter .
Fi g. 28
Fig. 24
GD
5.
Coincide
mark
on
the
ri ght
In case of disassembly
Tightening torque
Com chain
punch
tooth surface of the
2.1 kgm 115ft. Ibl
and
fllting
of
com chain, be
the
cam sprocket COm-
ca r e~
plete wi th the center
ful no t to drop clip
into
the
line of th e cylinder
cylinder
head, and combine
head .
sprocket
Pliers
of
cronk
Fig. 29
shaft by chain.
Fig. 25
6.
Cylinder head
Tie a wire at the end
,"
Beforehand,
ro cke r
arm,
valve
com
of chain to prevent
shaft
chain from dropping
should be subassem-
into the cylinder.
bled.
and
valve
Plasti c ham mer
Fi g_ 30
/~\\j' .
Fig . 26
~:;.;.
~~
Pay atten tion to "0
Fitt ing direction of clip;
fit
ring and gasket.
the jOint to the
direction of revolu~
tion
of
the
c ronk
Fi g . 27
t
53
52
- -------.--.- - --
C.
l. Cover
Assembly
Disassembly
Preca ution
Tools
Assembly
Disassembly
Precaution
Tools
5.
Clutch pressure plate
1.
In fitting L. cover , be
L. cover
To tighten p late setti ng
bolts, ti ghten
Pa ck ing
careful the oil fil ter
even ly ,
Dow e l pin
cover
as
not
ta bite
on a dowel pin of
the oi l filter shaf t.
T·Handle
driver 1#3 1
diagonally
shown
pi c ture.
forehead
them
in
the
Check ex·
istence of spring.
10'%/ socket wrench
10'%/ socket w r ench
Plastic hammer
Fig. 40
6.
2.
Oi l nlle r
Set
oil
fi lter
Clutch
drive
li fter
piece
sprocket pin facing
joint
In assembly, check op·
eralion of oi l metal
guide.
R. outward.
Fig. 37
r
-:-
..
7.
3.
Be ca reful a bout
Lock washer
c ripp le
Forehea d driver
snap ri ng remOver
Plasti c hammer
Fig. 42
4.
After
l ock nu t
tighte ning
fectly,
per·
tu r n up the
B.
Clut ch center
-
torque of lock wash·
er.
If not to rque
and
nut coincided,
nu t should be locke d
a fter turning to the
tightening direction
without loosing it.
Fig. 43
56
57
Precaution
Tools
Assembly
Disassembly
Disassembly
Precautio n
Tools
Assembly
9.
Clutch plate
Pay attention for order
Clutch friction disc
of fitting .
In
disassem b ly
and
do
it
assem b ly,
In
tightening
bolt of kick starter,
the
perpendicular ly to the
spindle
mission rr.o i n sha ft .
seen
hole.
Fi .;J. 44
Be care ful about size.
Fi g. 45
10.
Shift spindle
Fig. 46
11.
Shift drum stopper
drum
stoppc::r
guide
10"%11 socket wrench
1 7~'j{}/ socket wrench
fig. 47
58
mark
end of kick
cro nk sha ft and trans
Shift
stopper
59
on
the
sl arter
should
through
be
the
.::'---
D.
R. Cover
Oisossemblv
Assembly
Precaution
Tools
Disassembly
Precaution
Tools
Asseml;>ly
5.
1.
A.c. dynamo slarler
Starting moto r cable
After
slarler
assem-
b led, check rotation
of
the
sta rt er
sp rocket.
10'%1 socket w re nch
10%1 spanner
Fig. 49
2.
6.
Starting motor
A.C. dynamo Rotor
R. l. side CO ve r
14 '%1 socket wrench
T· Hondle
Plastic hammer
for ehead
Dynamo ro to r pu ll er
dri ve r 1#21
1 7"%11 spa nner
Fig. 50
Fig. 54
3.
7.
Starting motor
Sta rling
sprocket
st o pper
10'%1 socket wrench
10'%1 socket wrench
Plastic hammer
For ehead driver
Fig. 51
Fig. 55
4.
8.
Neutral sw i tch
Stoner sprocket
Fig. 52
Fi g. 56
60
61
-
~ f'~'
.
"~
.*,
"'. " - '
_' . .
'o:;"'~' ''''
E.
Mission (Crank) •
Disassembly
Disassembly
Precaution
Assembly
Assembly
Precauti on
Tools
Tools
5.
I.
Counter sha ft
Uppe r
crank
case
se tli ng nut
14'%, .s ocket wrench
Fig. 6 1
Fig. 57
2.
To set bear ing oil sea l
Under
c ronk
case
In
tightening nut and
do it secure ly.
se ll ing nut & bolt
bolt. foilow order
as shown in
starting
figure
temporary
10'%1 socket wrench
li ghtening and then
oclual lightening.
Plastic hamme r
Fig . 6 2
f ig . 5 8
3.
Pain t li qu id packing on
U nder cronk case
Ihe case .
N ote; leas e th e sur ·
face of packing be
•
fore po inting . Don"
I
us e with
attach ing
cleansing oil o r oil.
Point witho ut c hok-
ing oi l ho les.
Fi g. 59
4.
Main shaft
Fig. 60
.:. =-::',".
62
"
."
Fig . 63
·,.,
F.
Cylinder Head
Assembly
Disassembly
Precaution
Tools
Precaution
Assembly
Disass e mbly
Tool s
5.
1.
Valve
Cy linder head cap
Atla<;h
tog on Land
R. val ves not to be
mixed each other .
Valve lifter
Thin nose pl iers
23'%1 spanner
6.
2.
Rocke r arm crank pin
Rocke r arm
Contact br eaker
T·Handle
fo r ehead
dri ver 1#2)
In assemb ly rock arm
cr a nk p in, pay olt ention 10 Qute r d iamete r of inl et rocker
o r .ll cran k pi n a nd
of exhaust rocker
arm
pin
to
Roder arm crank pin
exira lor
in se rt
,j '
inside the cy linde r
he ad.
Forme r p in
is lar ge r than d iamete r of that
th e latter.
of
Fig . 69
3.
R.L.
cylinder
head
Cutting -g r oove s on the
side cove r
rocke r arm c rank pi n
T-Hand le
two places ar e
se t for oil passage
01
fo r ehe ad
driver (# 31
and r etre at fo r stud
bo l t.
So need spe-
T
cial attention to allocate pin to assem -
i
~
ble.
4.
Tap pet
7.
a diu sting
;
CO'll sholt lock nut
sc rew
Forehead dri ve-r
10'%/ sponner
Plastic hamme r
Tapp et adjust ing sock et wrench
c
•
-'J
..,...... """'
-'-.
.,
Fi g. 67
Fi g. 71
(>4
65
._0.
c
Preca ution
Tools
Assembly
Disassembly
8.
Disassembly
'
r
fa
~£
F7"
'«:Od"''Q'-e:==
Precaut ion
Tools
ASiembly
11.
R. com shoft
Forehead drive r
Plast ic hamme r
Cam sp r ocket camp.
Put the punched mark
upward
a nd
com
shaft r ocke r nut to
the r ight side .
Fig. 72
Fig. 76
Assembly
pr.oce s~
L. ca m shaft.
of
Valve sheet cutter
Aft er
coinciding spline, put
th e red line o f the
poi nt sha ft cam on
the
punched
mark
Plast ic hammer
of the cam sprocket
(facing upwardlthc n
Fig. 73 ·
insert.
Fig. 77
9.
Cam sha ft l ock nut
L. co m sha f t
I O/~I socket wrench
Fig . 74
10.
In
ass embly
shaft,
th e
cam
coinci de the
spot where a tooth
of spline of the c am
sprocket comple te is
la cking with the co r·
resp ond ing spot on
the
com shoft a nd
then in sert.
Fig. 75 ·
66
67
eG
y,;,-.......
."
G~
011 Pump
Disassembly
Assembly
Precaution
Disassembly
Precau ti on
Assembly
Tooli
Tools
4.
Side cover
Re fer
to
the
engine
minor overhaul and
assem bly.
T-H a ndle
forehead
driver 1#31
fig. 78
1.
5.
0;1 pump stra iner
Oi l pump side cover
0;1 p ump pocking B
dowel pin
0;1 receiver
Oi l pump body
O il pum p gear A
()
Oi l pump gear B
-
Oil pump drive gear
Fi g. 79
Fi g. 82
2.
Oil pump packing A
Dowe l pin
Fig. 80
3.
Snap rin g
C heck smoo th rU1ni ng
of the dr ive g ee,-,
o
Snap r in g remO ve r
()
Fig . 8 1
68
\,
~
(1
2 • . ENGINE (C872 , ' 77)
A.
Disassembly
Precaution
Assembly
Disa ssembly
Engine replacement
Tool s
Precaution
Assembly
Tools
1.
IL-sidel
Duo! seal
14'%1 spa nne r
4.
Fig. 83
l. exhaust pipe joint
2.
nul
Fuel lank setting bo ll
L. exhaust muffler
10'%, socket wrench
14'%1 sodel wren ch
14'~j;1
sp O'lncr (2
10'%1 socket wrenc h
Fig. 84
5.
Upper
cronk
case
Take out tubes A and
cover
8 slopping choke .
Fig . 85
3.
Gear change pedal
bar,
Slep bar
6.
In assembly the step
coincide
Spee d- ta chomete r
Ihe
cable
punched mark with
line of the bracket.
14'%1 socket wrench
10'%1 spO Me r
17nxn sponner
Fig . 86
Fig. 90
70
71
•
Assembly
Disassembly
Preca ution
Tools
7.
Disassembly
Pre caution
Tools
Assembly
11.
l. a ir cle a ner cover
R. exhaust pipe joint
Starling motor cable
nul
R. exhaust muffle r
10'%1 socket wrench
14 ' %11
10""n spanner
"
14 '%1 spa nne r
Refer to l. side
Fig . 91
tl.
12.
Air cl eaner connect-
Dynamo cover
ting lube
Throt1le
T-Hand le
wire (refer
forehead
driver (~21
to l. sidel
T-Handle
forehead
driver 1~21
9.
13.
Enfji ne selling bolt
R. crank case COve r
Clutch wire
D rive sp r ocket COV(' I
T- Ha ndle
forehead
driver 1#31
17 ""11 socket wrench
Forehead driv er
Fi g . 96
14.
10.
Dr i ve c hain
IR. sidel
Pliers
Brake pedal
Refer to the item of
Slep bar
frame.
Stop switch
14'%t
socket wrench
Refer to l. side
Fig . 94
72
73
Assembly
Disassembly
Pre caution
Tools
Disassembly
Pr ecaution
Tools
Assembly
19.
15.
Conta c t breakel
Air cleane r case
cove r
Conta c t breaker
T·Hondle
forehead
d river ( ~ 2 1
FIg. 100
20.
16.
Engine hanger bo lt
Throttle wire
17'%/ socket wrench
17'J;'/ spanner
FIg . JOJ
Fig . 97
21.
Engine selling bolt
17.
Airc l eo ne r
connec t·
About
refer
ing tube
throllic
to
wire
the
item
Insert T -Handle forehead driver.
out
the
driver
and
lay
of Engine Replace-
down
engine
to
ment
toke out the laller
for
Model
C8 72. 77
T-Ho ndle
forehead
driver (~ 2 1
driver.
14'%/ spanner
14 '%/ socket wrench
17"%1/ spanner
FIg. 98
18.
Engine w iring
FI, . 99
74
Take
former
75
f
":d
B.
Cylinder
c.
Disassembly
~----- .~~
Assembly
Precaution
To ois
'~r-==z=
-- .
-
. '.:.... .....
- -.",-~-
Engine mInor overhau l and assembly
Disassembly
Precaution
Toois
Assembly
1.
1.
Carburetter
R. L. Cylinder head
side cover
T·Ha ndle
forehead
driver (~ 3 )
10"}{1I spa nne r
Fig. 102
Fig. 103
2.
Cylinder head cove r
Cam chain tensioner
ReIer to Model
cn
77 Engine Replace·
men!.
76
77
_
-
_
~
-
=
-
=
=
-
__________
---- . ,
-0._'
.....
3.
FRAME (C872' · 77)
A.
Disassembly
Preca ution
Tools
Assembly
Rear Fork
Assembly
Disassembly
Precaution
Tools
5.
Drive chain
1.
Rear
brake
wire
compo
F;g. 108
14ry;'n sponner
6.
Fig. 104
Rear wheel
2.
Rear brake
stopper
Pliers.
arm
F;g. 109
14% spanner
7.
3.
Chain case
Coller Pin
Axle nul
Pliers
10% spanner
10'% socket wrench
Fig. 106
4.
8.
Rear whe e l oxle
R. rear cushion
PlaSTIC nemme
17~
socket wrench
17'%, spanner
Fig. 11 .
78
79
---'
.'
B.
Precaution
Tools
Assembly
Disassembly
Front fork
Disassembly
In
assembly. put
screwed side af the
I.
rear cushion under
bolt
hole
to
Precaution
Tools
Assembly
the
Head light
face
T· Handl e
fo rehe ad
outward .
drive r 1#21
Fig. 1 12
9.
F;g . 115
Exha ust
muffler
Refer 10 the previously
Change pedal
mentioned items of
Broke
Engine Repla·cement.
pedal
2.
Wiring
Dra w out on ly while,
Step bar
r ed an d b lue wires.
Fig . 11 6
10.
3.
R. step bar bradel
Wi r e Harn ess ferm i-
na l
I71/Xu socket w r enc h
Fi g . 1 1 ~
4.
II.
l. step bar bradet
Speedomete r cob l e
Tachomete r cable
Plier s
171J}{n socket wrench
Plastic hammer
Fig. 114
Fig. 118
80
81
Precaution
Assemb ly
Disassembly
Disassembly
Tools
5.
Precaution
Assembly
Tools
B.
Brake wire
Cotter pin 13 X 281
Front whee l axle nut
Pliers
14'%t spanne r
23'%, socket wrench
Fig. 123
9.
Front wheel axle
14% spanner
Plastic hammer
Fig. 120
Fig. 124
10.
6.
Front fork compo
Front brake stopper
Front fende r
arm
Plastic hammer
Forehead driver
10% spanner
Fig. 121
Fig . 125
11.
7.
Speedometer
Sta rter switch ass y
cable
H-handle
ass'y
Pliers
forehead
driver (#2 )
Fi g. 122
Fig. 126
82
83
Precaution
Tools
Assembly
Disassembly
12.
Disassembly
Precaution
Toois
Assembly
- - - ' -- -
16.
Thr ollie grip pipe
Hex. bolt 8 X 30
T-Handle
forehead
Steering handle pipe
driver (#2)
camp.
In assembly, pay attent ion
on
punched
mark.
14 ~n socket w r ench
13.
17.
Throttle wire camp.
Steering damper
knob comp o
lock spring
I
Damper lock spring
set bo l t.
14'%1 spanner
17'%, socket wrench
Fig. 128
F;g. 132
14.
18.
Clutch wire compo
Speedometer ass'y
fr ont
brake
wire
camp.
Clutch wire
adiust
bolt.
Fi xing nut
Pliers
19.
15.
Snap pin 6'%1
Front fork bolt
Sleering damper I
lock s;Jring nut
spring
{ Plate
Friction disk
Steering head st em
nut.
Stem nut
Pliers
26'%, spanner
35% spanner
F;g. 130
F;g. 134
84
85
- ,
- --.
Disossembl'y
Assembly
Precaution
Tools
Disassembiy
Preca ution
Tools
Assembly
23.
Front fender
Fork top br;dge
Toke
out
an
arrow
marked bo lt.
F;g . 135
Fig. 139
~4.
2
Steering head thread
Front fork compo
compo
Steering
top
corp
ra ce
F;g. 136
F;g. 140
22.
,..-,.J
Put
Steering stem compo
the
und er
front
fork
cover
with
--'~.
welded clip as the
.
~
..1
R side.
ej
"
•
- --"-"-,----- -------!
F;g. -137
Fig. 141
F;g . 138
86
87
CONSTRUCTION
CONSTRUCTION
1. POINTS OF CONSTRUCTIONAL DIFFERENCE BETWEEN
CONTENTS
1.
2.
3.
2S0, 300 MODEL C72, 77 AND CB72, 77.
DIFFERENCE BETWEEN C72· 77 & CB72 . 77
Honda 250. 300 super sport Model CB72. 77 has a newly designed chassis equipped
A.
Engine
. ... . .......... ... ........ . . ..... . . . ... . .. .. ...... . .
93
B.
Frame ....... . . .. · .• ···· · •· ··· · • ·· ··· · · ·•··· • •····• · · ···· · ··
93
with engine which partly reconst ructed from those of Model C72. 77. and aimed mainly
to be used as spo rts car maintaining availability as racer interchanging some of its pa rts .
As this engine is high rotation. high power type and chassis is light weight. high rigidity
ENG INE
A.
Main Parts of Engine
...... .•• . . . • •. ... ••.... . . .. • .. . .. . .....
95
type. the special constructional featurer comparing with Model C72. 77 could be cited
B.
Lubricating System .... . .. . . . • '.. .. .• • . .• •. ... •....•. . ..•• . ..•..
97
as follow.
C.
Ce ntr ifugal Oil Filter . . . .• • .•.. . . . ···••··· ···•·· •·· . .••. . . . . . . .
99
A.
POW ER TR ANSMISS ION
A.
Clu tch and Primary Chain. . . . . . . . . . . • . . . . • . . . . • . . . . • . . . . • . . . . .. 100
B.
T ransmissi'On Sys tem . .. . ... . . ....•... . .. . .. .. .......... . . .. . ..
103
C.
Final Driv e M ec hani sm
. .. . . . ...... . .. ..... . .. .. ........ . .. ....
109
Engine
1. Twin carbur etor
To rais e horse power adopted Twin carburetor system
iunction
of
suction
Reciprocating change
AUXI LI ARY PART S
A.
Funne l Type Br ea th er
B.
Kick Starter M echanism
C.
Cam Chain Tensioner
.. . . . . ... . .. . . , ..... ... .. . ... . . .. ... .
.... .. . . . .. . . .. . ... . .... .. .. .. . ..... . .
110
. ... . . . . ......•. .. • •. . . .. . . . . . ..•••.. • ..
111
.. .. .. ..... . . . ....... . ... ... .... .. .... . . .. .. .
. .. ... . 11 3
CARBURETTOR
6.
FRAME . ......... .. . . . .... .. . .. ... . . , ... ... .. . ... . . . .. .. .... .... . 118
7.
SUSP ENSION
A.
Front Wheel Suspension
B.
Rear Whee l Suspens ion
'
.... . . . ....... . ... .... . .. . . ..... ... .. .
... , .. . . ...... . .. . .. . ... . .. ...... .. . . .
Change control system suitable for high speed running and ra cing.
110
5.
e.
removing
manifold.
2.
4.
HONDA
120
121
3.
Kick of for wa rd step
ConSidering relation with frame. direc tion of step of kick arm was set forward .
4.
180 d egree (I-Type) cr ank angl e
To get stabil ity at high speed reducing vibration left and ri ght crank arm angle was
set as 180 degrees.
B. Frame
1. Fram e and rear fork o f steel t ub in g
To attain li ght w eight and raise rigidity main constructional member is constructed by
STEE RING SYSTEM
high carbon steel pipes.
.. ...... . . .... ... . . .. ............ . .... .. ... ...... . . . 123
A.
Handle
B.
Steering .... .. .. . . ..•.... .• • . . .. • . . ....•... • ... . .. . . ... . .... 124
2. Telescopic type fork
To raise stability at hi gh speed running on rou gh road maintaining rigidity. Telescopic
9 . . BRAKE INSTALLATION
type fork was ad opted on the fron t wheel suspension.
10.
11.
W HEEL
A.
Front Wheel
B.
Rear Wheel
. .... . . .. . . .. . . . . ... . ... .. .. . .... . ... . ... .. .. . . .
. .. . .... . .. . .... . . . .. . .... . .. . .. .. . . .. . .. .. .. . ..
128
129
Ai r Cleaner
B.
Muffler
. .. . . ...• ... .. .. . . . . . . . . . . . . .. .. •. .... .. . .. .... . 131
. . . . . . . . .. ..... . .. .• · · · ···· ·· ·· •... ... . ..•.... . . .. ..
91
132
Rear cushion of thr ee step ad justment
Rear cushi on is ad justable according to load and road condition.
4.
AUXILIARY EQUIPMENT
A.
3.
1B in ch ty p e
To enlarge bank angle and to help pleasant feeling
front wh eel 2.75- 18. and rear wheel 3.00- 18 .
93
on
rough
road.
equipped with
5.
2. ENG[NE
Speed . Tachometer
Speedmeter and Tachomet er were set in the sam e case.
A. Main parts of engine
Step and han dl e easy t 0 m0 ve or interchange
6.
To make eas y ri d ing posture
SUI't a bl e
for general, high speed Or race riding.
Cylinder and Cylinder Head are th e most important parts of engine and its construction,
material and its machining rote of precision affect engine performance.
Th is type of engine adopted most suitable O. H .V. type valve arrangement to attain
MEMO
cient combustion chamber form.
On the other hand the camshaft is set
in
effi-
th e cylinder
head and th e valves are actuated by Locker arm 10. H.C) , accordingly reciprocating parts
are redu ced very much compa rin g with other typ es.
CD
®
®
Breaker ar m
@
Point
®
®
®
®
T e rminel
Contact breake r fitting hole
CD
®
Oil fe lt
® Cam sprocket
Spring
Sc rew to fix contact point
Contact point
Fig. 2- 1.
94
Camshaft
Camshaft ny-wheel
95
@
Va lve rocker arm
®
®
®
®
®
Valve
Piston
Connecting rad
Cam chain
Cranksha ft
The cam sooft is driven by
chain
through
the
timing
gear reductioned
cylinder head is mode of light alloy, not only it is
light but
cellent as heat conductivity is good, and shope of
combustion
spherical one
to
get efficient combustion
of mixture
and
cooling
1/ 2 .
to
the
is
ex-
efficiency
chamber
also
As
is
attain
idea l
semi-
larger com-
B. LUbricating system
Construction and Ope ration
For Hondo 250, 300 oil
system is applied.
is
supplied
under pressure
by
gear
pump
The oil pump is attached under crankcase by
6
pump is shown in Fig. 2-5 and II I is driving gear and 121 driven gear .
As the cylinder is machined with high rate of precision cooling efficiency and lubrication are
mitted by driving gear 131 meshing with crankshaft gear.
favorabl e, accordingly wearing effect is ver y small.
pump, the· driving gear 1I I rotates to the arrOw direction
is used at the big end of the connecting
rod
to
Single row W
get
ample
type Needle Bearing
loading
capacity
at
the
the
of gear
driven
right
oil
Power is trans-
for operation
and
the
The
side
gear
121
sucking
oi l
from this side to feed the left side .
bearing.
On the other hand single raw Boll Bearings are used on the crankshaft,
where W
middle parts at 2 stations single raw the needle bearing are used to get
type
larger loading
capacity.
As crankshaft has on
rotates counterwise, then degree of vacuum inc reases on
wet-sump
bolts.
pression ratio.
As
and
Therefore each port
of
the
pump
should
be
burning or other troubles due to mol lubrication.
oil leakage through inadequate gop between
important
function
to
convert
reciprocating
motion
to
rotation,
carefully
gear
inspected
Such troubles
teeth
and
vacuum .
. h t t a ge t smoo th rev 01 u t'on
by putting balance w elg
I
.
The crankshaft can
Lubricating oil sumped in the crankcase is sucked by oil pump
running as it is balanced by dynamic balance on the
balancing
rotate
smooth
machine after complete
maching.
To reduce vibration a t high speed revolution and to get stability at
high
speed
running
the right and left cronk arm angle of Model CB72 , CB77-1 crankshaft is set 180 degree.
IFor M odel C72, C77 type angle is 360 degreel
CD
Fig. 2 ·2.
CD
®
®
o
®
®
®
®
®
CD
®
Type ·1 crankshaft
Piston
Ro lte r bearing
Connecting rod
R·crankshaft
6205 Z speciat ball bearing
Com chaim sprock et
l. crank shaft
Oil pump drive gear
Fig. 2-3.
Type·lt crankshaft
,
Fi g. 2 - 4.
Lubricating C irculation
97
96
after
pump
between gear face and pump body Or pump side cover causing
inertia force due to reciprocating motion of piston and connecting rod should be reduced
to
avoid
OCCur
due to
body,
or
drop of degree
of
to
main
engine
pass
through
the
,.,,~
under crankcase and L-crankcase COver th en the pipe line in splilled to
2-ways,
One
to the oil niter.
Oil cleaned in the oil niter is feeded to the crankcase where th e line is splilled again
to 2-ways, one is guided to the crankshaft through the center bearing
and
lubricate
the big end of connectin g rod and also the small end by splash ing, and another line
is guided up to the cylinderhead al ong the cylinder stud bolts from the
case to lubricate cam shaft and locker arm
separately in
the
front
armp in in the head th en drop in the cronk case through th e space
a nd
upper cronk
rear
locker
around the com
chain .
On th e other hand,
one line splilled in the L-c rank
case
cover
is
guided
into
the
transmission mainshaft through the oil guide metal w hich is nxed on the L-crank case
cover by spring , and th en drop in the
crank
caSe
lu bricating
L-crank
case
COver and
mission
gear
thr ough
oi l hole bored in the shaft.
C. Centrifugal oil filter
Oil Filter is located on the fr ont side of
I --
1--~I!
l. cover
___
!'
Mission
__
~f-t- I
I--
I
Cylind er head
I
Upper case
I
I _~
I
Mission gear
Crank sha ft
I
I
I
!
Cam shaft
C onnecting rod big end
I
I Connecti~g
· · ·····- ~I
l ~-
Oil sump
!
rod small end- I
.
CD
- » Forced lubricating line
---- 4
CD
®
®
is
cl eaned
and
separa ted by ce ntrifuga l fo rce driven by th e drive sprocket of th e crank shaft and chain.
O_ il _fi,oI_te_r_ __
I
~--...:!
oil
Splash lubric a ting line
Drive gear
®
®
Oi l filte r rotor
Rotor cop
52mm ci rcl ip
@ Oi l filter shaft
@ Filter shaft stopper pin
@ Oi l pump body
Oil pump ge ar [d riving gead
O il pum p gear Idriving ge ar I
CD
®
®
O il pump sidesover
Fig. 2 - 5.
98
99
3.
powm
TRANSMISSION
Power transmission is defined such mechanism as
to rear wheel.
rotation
of
crankshaft. is
transmitted
The first step of transmission from crankshaft to clutch is done by chain.
This clutch is wet multiple plate type, so there
is
no heat
generated
by
friction
and
also no noice perfectly.
As this transmission is such type of advance 4-step and constant meshing,
gear sound while in gear changing,
and consequently made
there
is
no
it possibl e to wid en rear
wheel driving power of powerful engine.
Further power is transmitted to the rear wheel sprocket by chain drive from the mission,
and through rear wheel dumper of rubber made
to
the
rear
wheel
sprocke t and
the
rear wheel torque is transmitted betwee n the final driven flange.
So that torque is transmitted very sm oothly without chain knock getting smooth running.
Especially
as
clutch
is located on th e mission shaft. made it possible to minimize
de-
deflection of crankshaft and also to stabilize clutch function reducin g clutch inertia.
A. Clutch and primary chain
Clutch
f I I Function and kinds
Function of clut ch is to cut Or engage
gear
or
starting
locating
between
power
th e
transmission
engine
and
the
in
ca Se
of
transmission
changing
mechanism.
Th erefore fineness of cutting and smoothness of engaging and disengaging
are
im-
portant feature.
Th ere are several kinds of clutch system as cone
clutch,
centrifugal
clutch,
plate clutch and single clutch, ond w e call wet type when merged in oil
multi-
and
dry
0
®
®
G:l
®
system when oil is not used inside.
f21 Construction and functi on
For Honda 250 , 300 we adopted type of wet multiplate clutch.
As shown in Fi g . 3-1
ill
®
®
IDisassembled fIgurel and Fig.
3-2
leross
®
L-cronk case cover
@ 6X 19 washer
O-ring
Clutch pressure plate
Clutch spring
@ Clutch lifter joint piece
@ Oi t guide metal pin
outer compo
@
fr ic tion disk
®
@
@
@
@
L-crank ca se cover packing
Oi l filter cover
57X3
Ctutch
Clutch
Clutch
Ctutch
plate
center
®
@J
@
there is clutch outer compl ete when crank case cover is taken out.
In
the
l · leg sealed under bolt
clutch
friction
disk 16.). by
clutch
6X74 cross head screw
/I
6X I O
/I
6 X 45
/I
6X35
/I
6XI6
Disasse~bled picture of clutch
clutch
On the other hand , wi th th e groove cut a long the outer perimeter of clutch outer,
the clutch friction disc is connected through
sandwitching
®
fIgurel ,
outer complete, clutch spring 1101 in set by 4 of 6 X 24 hexal bolts pressing clutch
pressure plate 191 and
oi l seal
@ 6X24 Hex bolt
Oil guide meta l
Oil guide metal spring
25'%1 cir clip
Fig. 3- 1.
sectional
@ 14257
plate
171.
fl ange
mating with said groove, and
the tra nsmission main shaft can rotate freely.
Inside of the clutch plate teeth are cut which
mesh
with
that
of
outer
part
of
clutch center 181, and the clutch center is connected with the transmission mainshaft
by
spline
a nd
rotates
with
181
171
and
191
as
a whole with th e transmission
Therefore in case of disengaging clutch, 191 161 171 161 171 161 171 161 171
151 are pressed by clutch
springs, ro tatin g power of crank
mission as a whole by friction.
mainshaft.
10 1
100
is
transmitted
181
to
and
th e
•
Inside of the clutch outer, the primary driven sprocket is nxed by rivetting and
as
primary chain is set on this sprocket, power is transmitted to the transmission main
shaft through the primary chain from the crank.
Hand le the clutch lever, the clutch lifter thread tUrns right by
clutchwire,
lifter thread is pushed out inside by the Screw inside of clutch
adjuster
and
the
nxed
on
the R crank case and push outside th e clutch lifter piece II II through clutch
lifter
rod.
As the clutch pressure plate 191 is pushed onside by
the
clutch
lifter
clutch spring I I 01 is compressed to free 161 171 . of each 4 pieces .
joint piece,
Therefore rota-
tion of 151 161 161 161 161 is not transmitted to 181 .
(N ote )
Number of dutch plate
and c lutch friction disk is four sheet each for Mode l el2 and 5 sheet seach
for Mode l Cll, CB72, 77.
CD
®
®
Clutch friction disk
L-crank case cover
6X 19 washe r
@ 6X24 Hex.bo lt
®
®
CD
Clutch spring
Clutch lifter jOint piece
®
®
®
Clutch pressure pl ate
Clutch center
Clutch pla te
@
@
@
Pr inting driven sprocket
®
Mission shaft
@l Clutch lifter rod
6mm rivet
Clutch outer
®
®
Clutch lever
Clutch lift er thread
@ Clutch adiuster
@ R crank case cover
...
Oil guide metal
Fig. 3 - 3.
Cross section of clutch for Model Cll. CB72, II
B. Transmission system
1, Function and kinds ,
CD
®
®
Clutch plate
Clutch spring
6mm bolt
@ Clutch center
®
Clutch lift er joint
®
25mm circlip
piece
Fig. 3- 2.
CD
®
®
®
Pressure plate
@ Clutch
L-crank case cover
®
@
@
6mm rivet
Clutch friction disk
Primary driven sprocket
Mission shaft
Cross section of clutch for Model
outer boss
Clutch lifter rod
@ Clutch lever
@ Clutch lifter thread
® Clutch adiuster
@ R-crank case cover
and
vert torqu e by means of meshing gears of different number of
shown
Fig. 3-4 if driving gear is smaller than driven
side will be smaller transmitting large torqu e.
gear,
teeth.
no. of rotation
As
of
the
in
driven
Here it is called reduction ratio showing
the ratio of each gear numbers.
T here are two systems of gear meshing for transmission of auto-bicycle i.e.
sliding system and constant meshing.
C72
103
102
con~
Following clutch, function of transmission is to convey power transmission,
selective
is transm itted from crank shaft to primary drive chain, clutch outer, clutch center and
transmissi on.
o
o
Reduction rat io = -
Torque ratio =
~
A
INa. of teeth AI
Relation between red uction ra tio and torqu e ratio
By selective sliding system, shift gea r is slided by
reduct ion rat io by changing gear to
be
meshed,
gea r shift
and
each gear ca n be rotated freely always each -gear
.•..
B
Drive gear
Driven gear
IN a. of teeth BI
Fig. 3-4.
A
by
in
fork
constant
meshing
to
get adequate
mcshing
state,
and
system,
ca n be
changed red uction ratio by actuating optional gear by means of special clutch.
Fig. 3- 6.
Fig. 3 - 5.
Cro~s
sectiona l figure of transmission
gear
Fig . 3- 7.
2.
Th e first
The second
Construction and Function
The transmission system of Honda 250 · 300 is constant mesh and advance 4 stage rotary
type.
In Fi g . 3-5 to Fig . 3-9, neutral, nrst, second, third and top stage are shown.
Fu nction of tra nsmission as shown in Fig. 3- 5 and Fig . 3- 10 is as follows, i.e . power
104
Explai ning in order, from
the
crank
rotation
is
transmitted
mission shaft is ro tated to turn th e low gear (71.
the kick-start er spindle 1191.
As the
coun ter shaft
105
The low
2
gear
to
th e clutch , a nd
gear
turns
sl iding
th e
over
191 which is conn ected
with the spline on the counter shaft complete can move freely axially, move
this
the left' side by gear shift fork to mate with 100 " gear IFig. 3-61 then the low
to., ·~'::.·::~·
CD
®
®
gea / :';':
14'%1 bush
Kick spind le meta l bush
Clutch lifter rod complete
@ 12.8 X 2.2 "0" ring
combines with the counter shaft as one body to transmit power to the top gear (121.
Here the axial movement of main shaft gear is restricted by the gear cotter (141 and
®
the set ring (151 but not restricted rotationally. (similarly counter shaft 3 gear (111.1
Transmission main shaft
®
Counter shaft 120TI
(j) l ow gear complete
0. Main shaft 2·gear
® Counter shaft 2-gear
@ Main shaft 3-gear
@ Counter shaft 3-gear
@ Top gear complete
@ Drive sprocket 15T
@ Gear cotter
@
@
33mm set ring
Drive sprocket fixing plate
@ 14mm bush C
@
@
@
@
@
@
@
@
@
@
@
Fig. 3- 8 .
®
The third
Primary drive chain IDK328.5611
Kick starter spindle
Kick spindle pawl
spring
push pin
/I
/I
Bal l bearing 6305 HS
/I
6206 HS
Roller 5 X 6.25
Oil sea l 30628
/I
14257
/I
8216 TC
Hex. bolt 6X 12
Fi g. 3- 10.
Similarly for the second, protrusion of main shaft 3 gear (101 combine with
mainshaft
2-gear 181
by actuating another shift
rotating mainshaft 2-gear
(81
connected
by
fork,
and
protrusion
power
with
is
that
of
transmitted
by
mainshaft
3-gear
(101
mounted on the spline of mainshaft transmitting to countergear (31 and by spline from
counter shaft to the top gear .
As for the third, protrusion of counter shaft 2 gear (91 combine with that of counter
shaft 3 gear (Ill to transmit power to the top gea r (121 through counter
shaft
(61.
And for the Top, mainshaft 3 gear (101 combine with the protrusion of the top gear
and rotation of mainshaft is transmitted straightly to the drive sprocket to drive
the
drive-chain.
not
As for the neutral, each protrusion is
not
combined
so
power
is
transfer to the top gear.
Other parts of the kick starter system
pawl spring (211.
low gear.
Fi g. 3- 9.
The fourth ITopl
106
are
kick
spindle
pawl
(201
and
kick
spindle
This pawl mates with the inside groove of the low gear to rotate '
When not kicked, the head part of this pawl is pushed by protruded part
inside crank case, and pawl is pulled in to free the gear.
C. Final drive mechanism
CD
®
®
o
®
®
CD
The drive mechanism from crank to t he rear wheel is called final drive
Neutral switch assembly
Geor shift fork
/I
guide pin
as
shown
in
Figure,
primary
reduction
/intermediate
mission, final drive Ipropeller shaft, final reductionl wheel and tyre.
roll er
Gear shift drum
Shift drum stopper guide complete
®
®
®
main ports are
/I
complete
1/
spr ing
setting plate
1/
Gear shift spindle complete
@
"
arm complete
@ Shift arm spring
@
1/
pin
@ Gear shift return spring
@ Shift return spring pin
®
Shift fork rod
@ Geor change pedol
@ Chonge pedol rubber
@)
Stopper arm setting
@
@
@
@
@
Kick starter stopper bolt
@
@
@
@
bolt
Shift arm spring washer
Shift fork pin lock washer
12254.5V oil seal
6 X 24 Hex. bolt
6X16
/I
6X12
/I
6X 12 plus screw
6 X 12 coller pin
Fig . 3- 11.
~'B~~ides, there is equipped a switch to indicate neu tral state, which put light on a indicator lamp when the rotary switch combin ed on th e shift drum is \ in
The shift mechanism to actuate the above mentioned counter
main shaft 3 gear is explained as follows.
shaft
2
neutral
state.
gear and
the
In Fig. 3-11 wh en the gear change pedal
1171 is pushed down, the gear shift spindle 1101 is turn ed , and conseque:ltly the gear
shift arm 1111 will tUrn the drum 151 being push ed by the
protrusion on th e left end
CD
®
®
o
Clutch
Mission shaft
®
®
CD
Drive chain
Final driven sprocket
Fig . 3- 12.
of this gear shift drum.
As there are shift fork guide pin 131 and guide pin roller 141 which fitted on the gear
shift fork 121 in the groove on the cent er part of th e shift
drum,
rotation
of drum
actuates gear shift fork to move along th e form of th e groove from side to side and
the shift gear is actuated.
Here gear shift return spring 1141 is
change pedal to original position
and
prepare
next
action
and
fitted
to
retu rn
shift drum
the
stopper
161 is guide 171 for it.
108
109
Driv e sprocket
Primary chain
Crank shaft
mechanism.
reduct ion),
The
clutch,
.,~
4. AUXll,lARY PARTS
A. Funnel type breather
Breather chamber of funnel type is located an the rear
case.
guided
case.
upper side
of
the
upper
crank
Inside the chamber breather body is supported by a spring and back pressure is
along
the
direction
as
shown
in
the
Figure separating oil to outside of crank
CD
®
®
Here a check valv e is fitted to avoid outside vapour to be sucked.
Kick starter spin
l ow gear comp lete
Kick spindle pane l
Fig . 4 - 2.
For Model CB72 , 77, cons idering relati on with the chassis , advance step kick system was
2
applied.
A piece of gear was set ins ide the R crank case cover to reverse direction of
rotati o n and can start engine
transmitting
rotat ional
power
to
the
kick
spindle
pawl.
IFig . 4-31
3
ill
®
®
5
fI- - - {
R. crank case cover compo
Ki ck storter
Kick arm
@ Kick starter
® Kick stort er
® Clutch lifter
7
Fig . 4 - 3 .
gear
pinion
spring
thread compo
C ronk case cover
C. Cam chain tensioner
a;J
@
®
®
®
®
<V
®
Breather body
Breather chamber
Breather va lve spring
Cott er pin
Breather valve body
Inside cam chain chamber located at center part of cylinder cam
Breather valve
Breather support spring
IOK219-94L1
is
set to transmit rotat iona l motion of crank to cam shaft, and cam chain tension is applied
Breather valve (plain view)
to make high speed motion of cam chain correctly and smoothly.
Fig . 4 - 1.
tension works to supress waving of chain
B. Kick starter mechanism
by
pressing cam
chain.
Here the
cam
In Figure 4-4,
chain
6mm
bolt fitted on the tensioner push bar be loosen, th e roller will be pushed out by a spring
Kick spindle pawl for Mad el C72, 77 mates
pawl spring to rotate low gear.
chain
with
the
inside groove
of
When not in kick, the head of pawl is
by kick spindle metal bush so that low g ear attains free state.
low
gear
pressed
by
dawn
to give a adequate tension on the chain.
According
can be done by this set SCrew.
Sure
To make
tightness
adjust putting the crank shaft at the lower dead paint.
11 1
110
.,
to
slackness
of chain,
of chain
it is
adjustment
favo rable
to
5. CARBURETTOR
The carburettar is a device fo r supplying fuel and ai r into the engine .
3
of the carburet o r w ill
depend upon such factors
The performance
as most suitable mixture proportion
of atomized fuel under all conditions of speed and load of the engine .
CD
®
®
4
Therefo re
Cam cha in te nsioner
Com chain tens ioner spring
must has precision for each port and high res istance
Tensioner hold er
performance for a long period, and so it is required inspection and maintenance.
@ 6mm bolt
®
Cam chain tens ioner push bar
®
Cam chain tensioner orm
Fig. 4 - 4 .
for wear to
it
aSSure th e reliable
Th e revised ports of Model C72 from Model C7 1 are as fo ll ow.
11 I Elimination of man ifold .
121 Fitting type Down Draft type.
131 Addition of power jet.
Comparing Model CB72, 77 with Model C72, 77 2-ca rb urett o r system was adopted to
increase Horse power by eliminating branch
jet mentioned above, when MJ.,
#
to
sucti on pos t.
is se t, the best condition
8000 rpm mixture becomes thin, but wh en MJ
0
#
Concern ing
th e power
is a t 4000 rpm,
and
at
is set at 8000 rp m th e best and at
4000 rpm becomes rich.
Therefore to get fav o rable conditi on bet w ee n 4000 rpm
and
8000 rpm , MJ.,
#
was
selec ted to apply th e power jet from 6000 rpm to meet high rotation developing perfo rma nce at med ium and high power.
CD
®
®
Cam chain guide ro ll er
CD
®
Center crank shaft
®
@ Cam chain
Cam spr ocket
R cam sh aft ny wheel
Cam chain tensioner
®
®
Fig. 4- 5.
Fig . 5 - 1.
Power iet system
113
112
Power iet
Blind plug
Powe r air iet
121 through the passage 1161, the valve seat 1171 and valve I1BI .
Consfructiqn
III Air from the air cleaner passes through the suction port Ill, lower side of the throttle
noat chamber,
the
noat
1191
means of the noat arm 1201.
valve 161, main bore IBI and into the cylinders.
will be restricted.
This air stream produces a partial vacuum in the area around the power nozzle 1241,
will
raise and
move
the valve
As fuel enters the
I1BI
upperward
When the valve touches the valve seat,
now of
As fuel level drops, the noat lowers, opening the valve to
fuel to enter the noat chamber.
Thus, any change in the fuel
by which fuel in the noat chamber 121 nows through power jet fuel pipe 1231, power
level
caUSes
responding movement of the noat, opening Or closing the valve to maintain
jet 1221 to the power nozzle 1241.
At this area,
fuel is
mixed
with
air
Then they are mixed with air nowing from the suction
port, vaporized and drawn into the cylinder IFig. 5-21.
121 Main Fuel system.
Air from
the
air
cleaner
passes
through
partial vacuum in th e area around the
the
suction
port
needle
jet
141,
Ill,
lower
side
Th is air
stream
by which
fuel
of
area, fu el is mixed with air Ibleed airl
introduced
hol es 191 provided around th e needle jet holder
through
131.
the
Then
air
fuel
in
jet
and
the
air
side of th e throttle valve.
Th en they are mixed
with
air
nowing
noat
this
and
the
travel
the
to
from
a
As
151
gap between the needle jet 141 and the jet needle 171. and discharge
the
produces
chamber 121 nows through the main jet 1101 into the needle jet holder 131.
Th ere is a
spring
installed,
vibration,
between
the
the
the
The choke valve 1211 must be in a closed position with the choke
a
(Or-
the
fuel
noat
the
needle
arm
1201.
Air from the suction part III passes through the outside 1121 of the
Fig. 5-2.
lower
suction
which regulates the rate of air now.
Th en air passes thr ough the
of the slow speed jet 1131 to th e slow
speed
jet
1131 where
stream from the orince 1151 provided with the bottom
of the
air
Screw
1111
bleed
holes
1141
into
fuel
jet
1131.
introduced
slow
speed
The rich mixture produced at this area discharges to the lower side
valve and is mixed with air nowing from th e suction
minar mixture adjustment is made by
Turn the air screw to the right to enrich the
port
III
means
mixture and
of
to
of the
and
drawn
the
the
air
left
thr ottle
into
screw
to
th e
111 1.
lean
the
Th e major mixture adjustment is made by replacing the slow speed jet 1131.
Replace th e jet with one carrying bigger number to enrich the mixture and
with
one
carrying smaller number to lean the mixture IFig. 5-21.
141 Fl oat chamber
The carburetor must supply the correct mixtures which suit to th e throttle opening and
the engine running speed.
.In this connection, the fuel level
The noat system is a device to maintain this constant height.
noat system is given in the following.
114
must
be
held
constant.
The operation of
Fuel from the tank enters
the
noat
the
chamber
lever
moved
wards, and in a open position with the choke lever moved downward, as shown
131 Slow speed fu el system Ipilot systeml.
mixture .
against
valve and its body at th e Iocatlon
.
h
were
the valve contracts
IFig. 5-21.
port, vaporized and drawn into the cylinder IFig. 5-21.
The
allow
151 Choke system
throttle valve 161 main bore IBI and into the cylinders.
cylinder.
fuel
introduced
level constant.
through the power air jet 1211.
by
Fig. 5-2.
115
upin
~~~~~~---
-
161 Adju~tment
01
High speed Fuel mixture adjustment
Fuel mixture between full and half open
main jet.
throttle
positions
is
controlled
To determine whether the main jet is correct, slightly close
by
the
the
choke
valve with the engine running at full throttle.
1. If the engine speed increases, the fuel mixture is too leon.
2. If the engine speed decreases, the main jet in correct Or too big .
Replace th e main jet as necessary ' in such caseS,
bl
Moderate speed Fuel mixture adjustment.
Fu el mixture between half and one eighth throttle positions
is
controlled
by
the
adjustable jet needle and cut away of thr ottle valve.
/
1. If the muffler is block smoking, th e mixture is too rich.
Lower the jet needle
to th e next lower position.
2. If th e engine misnres Or hesitates when accelerated or driven at moderate
speed, the mixture is too leon.
Raise the jet needle to the next upper position.
CII
®
®
The throttle valve cut away carrying larger number bring the mixture leaner while
one carrying smaller number bring the mixture rich er.
Since
cutaway affects the engine performance below one eighth
th e
change on
throttle
position,
th e
o
the
replacement of the throttle valve should be done carefully.
cI
Float
End of float valve
float arm
End of float
Fig. 5 - 3.
®
®
fuel standard level
Ci)
Main bore botton line
Ports of carbureter body
Measurement of fuel stondard level
Low speed Fuel mixture adjustment.
Fuel mixture between one eighth and idle throttle
positions
is
controlled
by
the
bl
air Screw and throttle cut away.
When the noat is Supported with nngers, nnd the position where the
is about to touch the top of the n
1. Adjustment must be done by the air Screw mostly.
Turn the air screw " in"
oat valve or
cl
2. If th e correct adjustment cannot be obtained by the turning of air screw,
At this position height diff. erence between th e
body should equal to h arid if it ',s mOre Or
171 Fuel level adjustment
bottom of main bore, which varies
among
each
H
measured
different engines .
h, of th e noat.
from
However,
the fuel level cannot be measured easily, it is recommend ed to determine
by
having
clearance
d
of
the
h of Pw 22
26.5 mm
h of Pw 26
22.5 mm
noat
this
and
the
amount,
carbureter
adjust
the
since
height
(Note]
At the tip of the float valve there is inserted a spring
h
t
w ich creeps inside when pushed.
As it
preven to show the actual position where the valve is
t
h
to be dosed, it is necessary to be cautious
Osee f e contact point between the float arm and float valve.
Float adjustment
01
en
less than
height, raiSing Or bending the noat arm carefully.
replace the throttle valve.
fuel level is determined by the height
position
arm
of 0.1 mm.
to enrich the mixture and "Out" to leon the mixture.
As shown in Fig. 5-3,
t.he
noat
Place the carbureter upside down.
116
11 7
6. FRAME
Construction of frame body
The frame supporting engine contacts with ground through the front and reor wheels and
is the skelton of whole chassis.
design.
Further it has important
The main function of frame
is
to
feature affecting
maintain chassis strength,
its form
supporting
and
engine,
/
rider, and load on the carrier, and has to endure shock due to roughness of rood through
tyre and shock absorber.
On th e other hand it requires rigidity from viewpoints of control ability, and further req ui res
light weight to attain better running performance.
Model
The frame body of Hondo 250 • 300
C72, 77 is, mode of steel of stress skin construction and adopted such croSs sec-
tionGI form as refreg erato r having round corner.
bending moment a nd torsion.
Th e type of form has high strength
Th erefore this would be most favorable form of
to
construc-
tion for mo'tor cycle frame having high rigidity from manufacturing viewpoints.
Especially welding is done by new type of seam welder to attain reliable connection and
also uniform products having beautiful outlook.
On
the
other hand
for
the
frame
of
Model CB72, 77 , as main strength members, hi gh corban steel tubings were adopted
to
attain li ght weight and to increase rigidity.
CD
Main pip e
@ Coil sett ing plate
@ Tube holder
R. sub-tube
® Battery support Stay
®
o
2
®
CV
Sub-tube cross-member
R. sub-tube ho lder
'8'
\V R.l . rear cushl'on
CD
®
bracket
upper
@
@
@
@
@
@
@
l . sub·tube holder
R. bottom plate
R. ste p holder p iece
Muffler setting pipe
Center p ipe
Steer ing head pipe
Fuel tonk ho lder
Key ho le
Gasoline tank
Corrier
Fig. 6- 2 .
Fr ome body for CB72, 77.
@ Spare seat
®
®
QD
CV
®
®
Fig . 6 - 1.
Rear fender stay
Reor fender
Shock obsober
Rear fork
Seal box
Frome body
Frame body for Model C72, 77.
118
119
@
@
Front down tube
Drivers tube
®
®
Engine hanger plate
l. sub-tu be
@ Main switch bradet
@ l . bottom p late
@
Center pipe bushing
®>
l. step holder piece
7 . SUSPENSION
A. Front wheel suspension
__ __._-._------ --_
/
2 77 ,'s made of pressed
The front fork of Model C 7,
steel
and
for M odel
CB72,
-
..
.
77
"-
.
-
"- " --;;;:~"-' -..
@!L-Jl
. 'd''yo
t
nd to attain better runn ing stability on
telescopic fork was adopted to increase rig,
rou gh road .
As the cushion, th e li nk system
made
possible
it
to
reduce
wheel
As shown in . th e Figure of sh ock a bso rber,
it consists o f the main
spring
The spring tak es up compression load and the
cylindrica l oil dumper.
and
Double
damper ta kes up
re coi ling force .
For M odel
C72,
77 ,
arm as one bo dy,
left
but
and
rig ht
f ron t cus h',ons
for M odel CB72, 77
there
are
is
combined
no
by
th e suspensio n
suspension arm.
..
lJ
base
variation and to attain better feeling on riding a nd better controllability.
In the oil
._,- '.
-:::::=',="=-::,,
CD
Fork drain cock packing
®
®
Fr on t damper va lve
®
®
for k pipe stopper ring
fr ont fork sea l housing
Front fork upper co ver
(j)
Fr on t fo rk rib
®
Fro nt fork upper cover
damper of Model CB7 2 , 77 there con tains wh i te spindle ail 220 cc, and maximum stroke
f ig .
7- 3.
@
Front fork bol t
@ Ring, 40.5 X 3.0
@ Front fork pipe guide
@ front fork washer
@ "0" ring, 9.4 X 2.4
@ fr ont fork caver pack ing
@ Front cushion spr ing
@ Fork bottom bridge
@ Front fork p ipe compo
@ 3346 10, oil seal
®
®
Fork top bridge
®
Front fork oi l sea l retainer
Fork piston knock pin
@ Front fork
@ Front fork
@
piston
bottom case
Front fork drain cock bo lt
Cr o ss section of Front cu sh ion of Model CB72. 7 7.
is 80 mm.
B. Rear wheel suspension
The rear w heel is pivot type conslructian equipped wilh also sh ock absorber.
The prin-
ciple of conslru cl ian of th e shock abso rber is alike Ihal
excepling
of
the
front
wheel
such point as side preSSure don' l act o n Ihe sliding part and co nstrucli o n of
Ihe absorber is differenl.
CD
®
®
@
Front 'cu shion bott o m meta l compo
Front cushion spr ing front damp er inner pipe
®
®
CD
Front damper piston
front damper col lar
Front damper oi l seal
f ron t da mper rod
Fi g. 7- 1.
Cross-section of Fr on t cush ion fo r Model e72, 77
3
!
'3
I
I
@
CD
front cushio n
®
Hinge
®
Suspens ion orm
CD
®
Supporting hinge
Whee l a xi s
suspension
syslem
on
Ihe
of rear fork affec l on feeling of riding greatly.
Ihe rear
fork o f Model CB72 , 77 , main slrength members was made of high carbon
steel lu bing to attain light weight and 10 raise rigidity.
CD
Rear cushion met a l compo
@
®
®
Rear cushion spring
®
®
Rear dam per inner-pipe
Fi g . 7 - 2 .
Fig .
120
the
on
pivot side as performance of sh ock absorber, manufacluring around th e pivot and ri gidity
As
Front cushi o n bebound st o pper spring
Special allenlion was pa id On
orifice
7- 4.
Rear rebound sto pper spring
Rear damper oi l seal
Re a r damper rod,
Cro ss -section of r ear cush io n of Model C72.
12 1
8 . STEERING SYSTEM
A. Steering handle
Special attention was paid in designing the Steering Handle as this affect feeling of riding
and easy control.
Especially for Model C72, it was aimed to toke riding posture easy to correspond quick
manipulation of control, wh;'ch would be determined by the form
and step.
®
Rear cushion rubber bushing
Rear cushion spring seat
(j) Rear cushion stopper
0)
CD
©
Rear damper nut
Rear damper rod guide
Fig . 7 - 5.
Rear dampe r valve
®
Rear damper oi l sea l
Rear damper case compo
Rear damper piston
(ill)
Rear cushion upper joint
@
@
@
Rear damper under joint
@ Rear
Rear Cushion rebound stopper
spring
®
®
®
@
@
@
@)
cushion upper case
Rear cushion spring
Rear damper rad
@
the
handle,
saddle
Moreover on control ports , adjustment equipments are attached according to
each ride rs' choice.
CD
of
These features could be said to symbolize Hondo 's kindness.
Rear damper valve stopper
Rear cushion bottom case
Rear damper piston nut
Rear cushion spring adjuster
Rear damper inner- pipe
Cross-section of rear cushion of Model CB72, 77.
In the cylind er of the rear cushion th ere contains 60~ spindle oil 37 cc for Model C72,
77 and 47 cc for Model CB72, 77.
When the rear wheel got shock rear cushion spring
is compressed to absorb it and rebounding force is restricted by the oil damper to give
adequate cushioning.
If the amount of oil contained in the damper is not su itable, effective stroke of . cushion
becomes to short or leaks oil Or sometimes become origin
cushion of Model CB72, 77 is deSigned to enable three
of
steps
shock
of
sound.
adjustment
The rear
11
according
to road cond ition and running stote.
CD
MEMO
L. front winker lens
(f) R.
®
L steering hand le lever
(j) H orn button
®
®
0) H ead light switch
@ L. grip rubber
®
stee r ing hand le lever
Throttle wire
Winker switch
@ R. grip rubber
@ Throttle lever
R. front winker lens
Fig . 8- 1
Handle of Model
en,
77.
The handle complete of Model CB72, 77 ,'s mode of One p,'ece a f steel tubing attached
to the fork top bridge by means of th e handle pipe
fixed on the front cush,'on by 2 front fork bolts.
make it easy to replace the hand le.
122
123
holder.
The
fork
top bridge
E h
ac wire is exposed in assembly
is
to
For Model CB72, 77, the steering stem which has cone
CD
®
lathe inside supported
front cushion by means of 8 X 32 hexagonal bolt is the rotational
head pipe and is important part for steering.
,
attached and can be adjusted according to
axis centering
On the steering stem,
road
condition,
on
runn ing
steering
the
frame
damper
state and
is
loading
condition.
®
CD
Speedo -Tackometer a ss'y
If th e knob of steering damper be turned to the ri ght, steering damper spring
®
Steering handle comp o
raised upward to cramp steering damper friction disk by means of steering damper plate
(3) Hondle pipe holder
0
A and B, consequently handle steering becomes heavy.
Steering damper knob
On
the contrary,
if the
nut
is
knob
be turned to th e left, steering damper spring nut is lowered to make gap between plates
.Fig . 8- 2.
Handle assembly of Model CB72, 77.
A and B to become easy steering. IFig . 8-41
B. Steering
Construction of steering of Model C72, 77, as shown in the Figure, is such having ball
bearing and steering damper 01 friction plate system
to
meel
requir emenl
from
conlral-
labilily and slability 01 low and high speed running.
;
CD
®
Damper lock spring set bolt
®
Steering damper lock spring
@
;
®
®
CD
Steering damper knob compo
Steering head stem nut
Fork top bridge
Steering top thread
Steering bottom cone rcce
®
Steering head dust seal
®
Steering damper friction disk
@
@
Steering damper plote B
Steering damper spring
@ Cotter pin, 2.0 X 15
@
Steering top cone ra ce
@ Steel boll, 1/4"
@ Steering top ball race
@ Ste ering head pi8e
@
Steering stem
y
@ Steering bottom boll roce
@ Steel boll, 1/4"
@ Steer ing domper plote A
@
@
Fig. 8 - 4.
F·•g . 8 - 3 .
Steering damper spring nut
Cr oss section of steering of Model CB72, 77.
Crass section of steering head of Model C72, 77 .
124
Steering damper lock nut
125
...
~
,
9. BRAKE .INSTALLATION
6
As reliability and durability of Brake installation ore indispensable cond,tion for it, manufacturing Brake was paid special attention.
Reor wheel braki ng is done by
the brake lining installed is the brake drum which
is actuated
by
link
expanding
motion
to
tUrn
the brake cam by pushing right foot.
Here speci al attention was paid to disci pate fr icti on heat generated to get better
bility.
For the fro nt brake, by right hand operation wire transmits force
to work
duraa nd
brake machanism is alike with the rea r Installation.
3
®
Fig . 9-3.
MEMO
/
CD
Broke Cam
®
Brake lining
@ Brake drum
Fig . 9 - 1 .
CD
®
@
0
®
Brake
Brake
Brake
Brake
Broke
shoe width 30
shoe onker pin
drum inner dio
shoe out dio
cam
Fig. 9- 2
12 7
126
Front fork
B. Rear wheel
10. CONSTRUCTION OF WHEEL
The rear wheel of Model C72, 77 is
A. Front wh ee l
Front wheel body made of aluminium cast 'lng of whole width hub containing ball bearings
and brake drum inside is fitted with brake panel and speed meter unit by wheel axis and
nuts.
To assemble the front wheel to the chassis,
slide pipe by the axle fiItting.
fit on
React ion occured during
left side bearing through the stopper of the brake
the
lower
braking can
panel.
end
be
of front
caught
fork
by the
consisted
of wheel
bearing,
rear wheel
hub
of
almin ium equipped with the brake drum, the final drive nange serving chain case partially
and brake panel.
On the left side, the
brake
panel
is equipped
collar, and between the wheel hub and the final drive nange there
through
is
the distance
fitted
rear
wheel
damper.
On the right side of the wheel hub containing ball bearing, the chain
through the final drive nange fitted with
the
rear wheel
damper
and
sprocket, and is tighten on the rear axle passing through the left side
case
the
is equipped
final
of the
driven
rear
fork
braking
and
through the distance collar on th e left side.
The rear wheel damper absorb not only abrupt variation of rotation during
driving force of the rear wheel hub, but also is useful to protect transmission mechanism.
Th e rear wheel of Model CB72, 77 is consisted of ball bearing 163041, the
rear
wheel
hub of alminium casting equipped with the brake drum and the brake panel.
On the left side there equipped the rear brake panel of twin cam type through the panel
side collar and on the right side of th e wheel hub,
hub and
the
nnal
driven
sprocket
are fixed by the sprocket setting bolt. and nxed on the rear fork by the rear axle through
the rear side collar.
Fi g. 10-2.
Fig. 10 - 1.
To draw aut the rear whee l from the frame (Model CB72, 771
Cross section of front hub
128
129
1 1. AUXILIARY EQUIPMENT
A. Air cleaner
Th e Air cleaner element made of niter paper is stored at the
center part
utilizing a point of excellence that the frame is made of steel sheet.
of
the
body .
It is aimed to get
better niter effect by expanding surface area and also to prevent rain water to enter.
For Model CB72, 77, as 2 carbureters are equipped, air cleaners are nxed on both sides
each.
CD
®
Rea r whee l damper
Fig . 10- 3.
Final drive flan,ge
®
Final driven sprocket
Cross section of Rear hub
CD
Air cleaner connecting tube
Fig , 11 - 1.
®
Air cleaner el ement
'Air cleaner of Model :C72, ~77,
-/
CD
®
®
Air cleaner connecting tube
Air cle a ner element
R. a ir cl eaner support stay
@) Tool box complete
®
Fig. 1.1 - 2 .
130
l. air cl eaner support stay
Air cl eaner for CB 72, 77.
13 1
B.
Muffl~r
Construction of exhaust Muffler.
to muffler.
Exhaust pipe conducts exhaust gas fr om
cylinder
head
Curvetu re of this pipe affects horse power developed exh aust gas c onducted
thr ough exhaust pipe is damper inside of muffler by chockin g passage a nd further discipate
ELECTRIC EQUIPMENT
sound at the d iffuser pipe to get silencing effect.
CD
Fig . 11 - 3.
Diffuser pipe
1.
Ignition system (Ignition coil, magn eto, contact breaker, spark plug)
2.
El ectric po wer generator (Rotor typ e A.C. Generator, DC Dynamo)
3.
Rectifi e r (Selenium rectifier)
4.
Batte r y
5.
Loading 'illum in at ion light , winker, horn, start er)
Cross section of Muffler of Model C72, 77.
El ectric system is impor tant par! for th e bicy cle alike nervOus system for humankind.
partial damage at engine ignition, light a t night or horn
CD
Fig . 11 - 4.
Muffler
®
smooth running .
Diffuser pipe
Cross seclion of Muffler of Model CB72, 77
We adhere on
JI S standard
from
function
viewp oin t of
will
affect
quite
Even
often
manufacturing ' and
a
its
traffic
transportation vehicle law and security standard for laws & standards.
I
MEMO
132
133
CONTENTS
1.
SYSTEM
A.
Igniti on Circuit ............ ... ....... . ..... ... .....• . . ... • .. . 137
B.
Contact Br~aker
C.
Condense r. . .. .. . .... .. ......... . ..... .. . ...... . .. .. . . . . . . . . 14 3
D.
Spark Plug .. .. . .. ..... . . ..... . .. .. .. ................. . . .. ... 144
E.
Plug Construction .... .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
. .. .. . ........ . . .... . . ..... . .. ... .... . . . .. .. 140
Wiring Diagram ... .. .... .. . . ......... ... ..... ••. . . . .. ... .. . . . 150
2.
3.
CHARGING SYSTEM
A.
A.c.
B.
Ce lenium Recliner ... .. ... ..... . . . . . . .. .... .. . . ......... . ..... 154
C.
Battery . .... .. .. ....... .... • ..................... . . ... ..... 156
D.
Cell -Starter ....... ........... . .... . ..... ....... ... . . .. ... . . 162
E.
Ma intenance of Starting Motor .. . . ....•.... .... ...... .. .... . .. 166
F.
Starter Magnetic Switch . . ............. ....... ... ... ...... . . . _ 169
Generato r. .... .. ...... .. .. ... . .... . . .. ........... . ... . . 152
SAFE GUARD PARTS. .... .. .... . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17 1
135
1. SYSTEM OF ELECTRIC EQUIPMENT
As ignition system, ignition coil and contact breaker are used.
Rotor-type A.C. Generator
For electric
generato,.
is used, charging battery through selenium rectiner and dis-
charging according to several loading.
CD
®
®
H ead li ght
H orn
Main switch
Wire harness
Ignition coil
®
Rotor-type AC. Generator
®
o
(j) Relay
®
Selenium recti fire
®
Battery
@ Stop switch
@ Tai l or st op light
Fig . 11 - 1.
A. Ignition circuit
J, Ignition system
In gasoline engine, at the favorable time
of
the
uppermost
position of compression
stroke mixture gas should be burned and exploded by any means of ignition.
For both Model C. and Model CB, high tension battery
IFig. J J-21.
ignition
system
'.
ill
®
®
Ignition coil
Condenser
Contact breaker
G) Spark plug
Fig . 11 -2 .
Ignitioil system
137
)
is adopted
2,
CD
®
®
Battery
Insulation
Ignition coil
@ Secondary side
® Primary side
Ignition coil
Ignition coil is the same construction with that for Model
C72.
For
Model
77-1 type, th ere equipped with one c oil each corresponding to 2 cylinders
left, as the crank shaft angle is 180 degree.
CB72,
right
a nd
But for Model CB72, 77-11 type, alike
Model C72, one coil of simultaneous ignition system is equipped as
the
crank
shaft
®
Primary current
ill
Contact breaker
®
Poin t cam
®
Condenser
@ Spark plug
angle is 360 degree (Fig. 11-3 1.
Fig . 11 - 5 .
B.
Function diagram of Ignition coil of Model CB72, 77.
Functi on of ignition coi l
Th e principle of ignition coil is similar to that
Fi g. 1 1- 5, rotating cam axle and crank w ith
of
induction
constant
coil.
periodi c al
As
shown
relati o n,
in
th ere
generates high voltage on th e secondary coil as fo ll ows.
CD
®
fig . 11 - 3 .
a.
L. R. coi l for I -typ e
Coil for II-type
When th e point of th e contact breaker is closed primary current nows in
the
directions as sh own by arrow and generates magne tic flux inside th e iron COre.
b.
Ignilion co il
When the point is opened by th e cam, th e mag netic nux which is generating
by primary current is going to disappear sudden ly.
c.
A.
Construct ion o f Ignition coil
number of winding , th ere
genera tes hig h vol tage in th e sec o ndary c oi l.
Ignit ion coi l is shown in Fig . 1 1- 4 wh ere nne
enamel
wire
of
0.08 mm
dia
wound over the iron COre about I 000 - 2 000 rounds as th e secondary c o il
is
d.
And stored in the cylindrical case
after insulataing
process
Here generated high voltage will charge on distributed
sta tic
elec tric
of the secondary coil itself, then as it voltage increase, furth er start
on
vo lume
charging
on volum e of high tension cord a nd pl ug continuing incre ase o f voltage.
which further enamel wire of 0.6 mm dia is wound over i t about 200 - 300 rounds
as th e primary coil.
Due to large variati o n of magnet ic nux and large
e.
When vo ltage increases up to ampl e amount,
gap.
and drawing out th e terminals (Fig. 11 -41.
spark
will
occu r
As soon as spark started sparking voltage drops d own
at
th e
plug
instantaneously.
Accarding ly electric load charged on th e distributed static electric vo lume will
be discharged to tally. (volumetric sparkl.
A nd co ntinues d ischarge of energy
c o ntained in th e wire by disappearing magnet,ic nux. (Inductio n sparkl
f.
®
~-=-
approaches d own
to zerO instantly where
voltag e no
more
maintain spark voltage and discharging spark di sappears.
CD
®
®
to
@
l®
®
c_
®
G:'
Fig . 11 - 4.
Magne tic nux
Pri mary terminal
g.
Secondary term ina l
vibra tion inside secondary and primary coi l. and disappeqr acting as re sistance
Insulation
Iron core
Primary coil
Secondary coil
Still energy in wire due to remainin g 'minute magnetic nux w il l generate da mping
loss on th e cir cui t.
h.
Th en returning cam angle to original state to actuate the
function
as
stated
(0 1 to foll ow th e same process repeatedly (Fig . 11- 5 - Fig. 11 -71.
Cross sect ion of Ignition coil
!1
.,
139
138
'.
G
r~,,
CD
'
,, "
<,
,
®
®
8
,,
Fig . 11 - 6.
,.
wear of th e cam follower grease should be applied on oil felt.
Contact breaker
Required characteristics for point are as fallow.
Point cam
Condenser
@
Battery
+
Insulation
®
®
®
®
II
ene ra y co ntact point~'pressure is desi~nated between 700 and 900 gr, and to
11 H igh unti wearing property.
21 High heat conductivity.
31 H igh melting point.
Ignition coil
Primary coil
41 Hi gh unti oxydation.
Secondary coil
Spark plug
51 Have a moderate hardness.
Function of IgniHon coil of Model C72, 77, CB72, 77.
CD
Fixing hole of contact breaker
®
Oil felt
®
Breaker arm
@ Paint
®
®
CD
®
Spark gap
Contact number of conlact
breaker per
(f)
Point fixing screw
®
Base of COnfact point
minute
®
Fig. 11 - 7.
Termi na l
Spring
Fig . 11 - 8 .
Spark ' plug gap diagram.
&1 ..... 4
, '.
B. Cont oc t bre ake r
Th e contact breaker is a important part of mechanism to operate contacting and breaking
the primary circuit of the ignition coil Or magneto ignition
coil
securely.
It
inside of th e magneto for a rotary axis type magneto and fitted on the fixed
a combined nywheel magneto type but for separated nywheel type and
type the contact breaker is each one
unit.
The
contact
breaker
is
is
stored
stand
battery
Contact breaker
assembly
ignition
consis ted
of
th e
terminal
of
th e
breaker arm point on the base (movable contact point and fixed pOintl,
Fi g. 11- 9.
for
CD
®
primary wire, spring and oiled felt.
2 paints for Model CB 72,
77·1 type
1 paints for Model C72,
77, for CB72, 77· 11 type
The breaker arm is made of bakelite impregnated with cloth or pressed thin steel attached
a
cam
follower on its end.
On its other end of each part
movable
contact
point
is
fitted and insulated from base elec trically.
Fig. 11 - 10.
Function of the contact breaker is required to move very li ghtly , so it is designed to be
small size, lize, light weight and strong to make inertia small.
It is necessary to
constant spring load to avoid chattering while in sh ort of the point.
put
of Model CB72,
77·1 type
a
On the other hand
ther e is other rest ri ction of spring strength to avoid disordering of firing
timing
due
to
.~
.
'
,.
wear of sliding part of the cam follower.
140
Contact breaker
141
prevent
~
"1
,r"~
's applied
Sparking is
Generally for automotive use, 4 ~ 5 mm T angs ten I
.
· nd breaking of timing of crank shaft and cam
magneto com contacting a
generated
by
shaft
th e
by
contact breaker.
•
:::y
;
CD
;
'\00
Fig. 11 - 13 .
•
~ .0 0
CD
Point cam profll IMadel CB72, 77 and Model CB72, 77-11 Type
[Note)
Surface of point becomes rough with working
time
wear if attached oil or grease on the pOint surface.
..
impossible.
Contact breaker of Model C72, 77, and Model CB72, 77-11 type
One cam is profiled at th e end of th e
po int
shaft
connected
with
th e
spark
advance
72, 77-1 type, and 2 sets of conta c t breakers
inside of the cylinder head for Model CB
cor rect timing
are set relativ ely at 90 degree on the base, and designed to operate at
of La nd R cylinde rs.
elapse.
Esp ecia lly
there
occurs
extraordinary
Furth er if attached oil or greas e on the point
surfa ce be left alone for a long time, it solidifies and forms insulating surface to effect ignition
-----~.:,;;..
Fig . 11 - 11.
Cam
77-1 type .
2 coils, 2 points, 1 mount cam fo r Model CB72,
be
So special pr ecaution is needed to prevent atta ching oil.
If th e surface of point becomes rough or disty, use a fine file
and adjust, and if case is more
worser, ta ke
out
the
contact
or
sandpaper
breaker
to
bose
and
the
In
this
breaker base and th e breaker arm , poli sh both contact surfaces with oil stone.
case special attentio n is needed to avo id one sid e wear.
polish
Th is one side wearing affects
very bad innuence for a new part or repaired port.
Th erefore cen tering and parallel adjustment of both contact point is essent ial requirement.
Also if there is found too much ploy within axle hole of th e breaker arm
it
is
needed
to replace with new one,
On th e other hand , terminals of contact brea ker and insulating
ports
maintain ample insulating standard, so tha t special precaution is
required
avoiding vapour, oil, dirt to be attached.
CD
Fig, 11 - 12 ,
CD
One mount co m
of wire have
to
keep
to
clean
In case of adjustment of th e surface of point ·
wipe its surface with clean cloth stained with trichrene to avoid
grease,
oil
or
dirt to
be attached.
Point shaft com profol IModel CB72, 77-1 typel
C. Condenser
Function of condenser is to ovoid harmful spark be tween points, and if taken its volume
For Model C72, 77 and
Model CB72 , 77, 2 cam are profiled on
1 contact breaker is fixed on th e base.
Here simultaneous
th e point
ignition
system
as explained in th e paragraph about th e ignition coil
Model CB72 , 77-11 type ,
shaft
and
is adopted
value too large spark performance becomes worse.
generally i t is selected
adequate value between 0.1 and 0.35 microfarad.
On th e other h;nd it is required such f eatu re to resist high voltage as high
.
2
s and simultan eous spark.
coil, 1 pOint,
cam
14 3
142
The refo re
voltage
of
to make combustion of mixture gas by high voltage spark occured spark gap within plug
So it is pret the Point opening instance.
d
several hund red volt acts on the can ense r a
in the JIS standard that it should resist more than one minute under such condiscribed
A.c. 700V 150 or 60 clsl maintaining insulation of more than 5 MQ after heating
tion as
in the combustion chamber.
01
Conditions needed to embody for spark plug.
Th ere are nve subjects to be solved to fulnl
30 minutes at 80°C Ifig. 11-1 4, 11- 151.
its
function
perfectly,
which
will
be
always
tries
to
explained as follows .
IAI
Current,
Electric current nows through the shortest way, and
spark out of spark gap.
At manual temperature electric insulating character of
insulation is high, but at high temperature
this
character decreases.
Therefore
it is needed high insulation material which is hard to decrease its character even
at high temperature.
IBI
Explosion pressure
Inside the cylinder, 35 ~ 45 atmospheric pressure due to explosion always
path to escape.
. ..:....___ . . . .
....,...,.:.:.."' __
.
~
Fig . 11 - 14.
;~_..:u..
'.'--.
seeks
If air tightness of plug is inadequate, combustion gas of high
temperature will penetrate inside it to loose its function due to overheating .
Condenser IModel CB72. 77-1 typel
ICi
Combustion head.
Tempe rature of combustion of mixture gas will reach up to 2000°C.
to disci pate this heat sooner
,,
to
develop
engine
performance
It is needed
preventing
over
heating of plug , sparking in advance or burning electrode.
f
.
IDI
Carbon in case of incomplete combustion
If get dirty on the insulating part, engine will
fail
its smooth
ru nning
due
to
high voltage leaks partially and poor sparking.
'.
.
~
:..
..
~
lEI
,
Lead compound
4-ethyl lead is contained in
;
..
,,,
' ~~--"~
Fig . 11 - 15 .
--'-
.-
gasoline
to
compound is made due to combustion.
control
explosion,
and
lead
oxidi zed
If it is deposited on the plug, thi s com-
Condenser IModel C72, 77 and Model CB72, 77 · 11 typel
pound becomes a medium
having
conductivity
voltage current will escape as explained
Simple test for condenser is done like the
following.
After
checking
insulating
By use of the service tester it can be tested preci-
high
before.
Electrode
As material of electrode it is requi red to be
high heat conductivity. high resistant to
D. Spark plug
and
or
it
takes
manufacture.
hard
oxidation,
to wear,
high
low
sparking
conductivity
and
voltage.
easy
At present Nickel alloy or heat resistant alloy is used IFig. 1 1- 171.
magneto
145
144
and
E. Construction of plug
01
'c harge of starting engine, receiving high voltage generated by ignition coil
temperature
Here is shown the plug used generally for automobile IFig. 11-161.
sely volume value and insulating performance.
· . 't'
t
of engine,
Spork plug plays the mGst important part wit h In 19n1 Ion sys em
high
value
running, then
by mega, disconnect both poles of condenser from mega while mega is
it is decided
short both poles by wire. At this instance, if spark occurs large enough,
the volume value is good standard.
at
to
.,,#
cl
C once rning plug insulator IInsulator of specia l high alumina substancel
Chara cteristic
of insulator a nd spark plug
c
>
0
CD
®
®
Adhesive
Wire pa cking
Plate packing
0) Central pale
® Screw width
® La teral pale
~
Insulator {with corrugation}
Powder fi lled
_____l-:-@
%
1 SiO,
90.2 1
(hexago nall
%1
g/ cc
7.1
3.51
1
M ain benefits of this insulato r are as following,
"-"-"-T
Fig. 11 - 16.
M.Q
ci
~
<{
AI20,
®
Insulation r esist a nce
a.
a.
E
~
T erminal nut
@ Span ne r part
@ Main body
@ Gasket
@ Spark gap
C
(;
®
®
0,
Compositions
Pl ug const ru ction
IAI
As insula ting charactor is excellent, it is not trouble of misfire due to decreasing of
insulating charactor at high
Fig . 11 - 17.
speed
loading
condition
with
preventing
effect
of
nush over by t he head corrugation.
r
CD
®
®
Iron wire
Chpper wire
Special nickel al loy
lSI
Due to hi g h heat co nducti vity, heat conducted to plug can be d iscipated
quickly
preventing ove r heat.
COnstruction of elec trode
ICi
Due to high resisting character to heat shock, th ere is no troubl e of damage on
the insu lator by sudden rais e and ' drop of heat no
gas leakage du e
to · strong
construction.
bl
Insulater
As insulato r , special high alumina substance is used mainly.
excellent
characte r
comparing
with
that
of
fam ed
foreign
To join the central electrode with insulator, and insulator with main metal
This material has a very
product.
Th is
special powder is used.
superb
prevailed
method
ai rcraft plug manufacturing and co mparing usual cement adhesio n.
cha ra c ter can be attributed to high con tent of alumina and a perfect material refine ry
process and can maintain high performance due to burning process in high
This way of filling powder is
is perfe ct for long ra nge use
tempera-
acc ording ly
central
electrode
can
Air
body,
in
the
tightness
discipate heat
evenly and distribute heat evenly.
ture tunn el oven IFig . 11-1 81.
Amount of wear of electrode is indistrict.
is adopted to ease hea t discipat ion
and
Larger si ze of diameter
to
get
least
wear
having heat resi stant chara c ter was select ed corresp onding to
of high compression and high rotation .
CD
®
?pecial high al umina substance
Corru gation (to prevent blush over)
dl
Heat value of plug
Fa vorable condition for plug function
Insulator
147
146
special
alloy
su ch circumstances
Very st rict testing is done before
using
as even a minute crock in the ma ter ia l might be the couse of extraordinary wear.
al
Fig . 11 - 18 .
and
of electrode
Ig,.,ition port of plug is up to be dirty by carbon generated
by
combustion
during engine revolution or by ail penetrated into the combustion chamber.
deposit is electric
electricity.
conductible
itself.
and
makes
short
circuit
of
gas
This
high voltage
Accordingly weaken spark to decrease engine power misfiring and
worst case will stop engine revolution.
in
To prevent such phenomenon surface
of
insulator should be heated enough to cut off carbon deposited. and this is called
"self cleaning temperature".
labout 450°
On the other hand. it burned sparking port of plug at higher temperatur e.
ing part will become over heated
ill
~ 600°C according to engine statel.
point which
invites harmful knocking
®
spark-
should
Therefore it is requested tnat temperature of whole body of
to burn
be
maintained
less
according to engine statel.
than
that
of
premature
As a result it can be
spark
®
"sparking
part
of
plug
Fig . 11 - 20 .
II.
...
Escaping of heat
•
Heat received f rom combustion gas escapes as
shown
in the figure and sparking port maintains a certain tem-
perature baloncing heat quantity escaping and receiving.
cI
Necessity of different types of plug
having each
Different plug for heat condition
plug
is no good if too cooled also if too hot".
bl
High temperature use
Icald type}
sparking. Iless than 800°C
said
Medium temperatu re use
Im edium type}
mixture gas before hand than sparking the plug. which affect decreasing of engine
power.
Low temperature use
Iha t type}
W~
®
A
Fig . 11 - 21.
B
g
®
<D
®
Smooth running
@
Ignition too ea~ l y
Dirty
A; Low power
B;
Hi gh power
H a t type plug \for low temperature usel
dif-
ferent heat value.-Difference of heat quantity recieved
by each plug.
Heat quantity of
plug
received
MEMO
from
engine depend on kinds of engine lair cooled o r water
cooled. 2 cyle or 4 cylel. design
shape of combustion chamber.
Icompression
ratio.
Fig . 11 - 19.
Way of escaping
heat
plug positionl and run-
ning state Ispeed. loading . different
fuel.
flat
"
ground
or climbing slopel greatly.
Therefore it is necessary to furnish different types of plug to function satisfactorily
under each different operating condition.
"h eat vave of plug". and it is determined
and material.
This rate of escaping of heat is called
by
its
construction.
form.
dimension
It is called "cold type" Ifor high temperature usel which disci pates
heat eaSily and is hard to be over heated . and on the
hard to discipate heat and easy to be heated is
called
contrary
"Hot
such
type"
types
lIow
as
tem-
perature usel.
In Fig. 11 -20. difference between types functionally ore shown.
•
149
148
".
.
~\
.'
.-
~
-/'
,
~~.~.
300.(MODEL C72, C77)
WIRING DIAGRAM . OF HONDA 250 &
WinkerSw.& 5tarter Button.
t,r:
R Rear l'Iin.ker
RFron.i Winker
L~mp ,/01'1
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1-)~ . .',' ~t:
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Starterl1agndic 5w:.
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ignition
CoiL
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8/41'1
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L. Fron.t . . ~ Horn Button
Lamp lOW
Winker
Lamp.
. &.Dim. mer SIVo
~:
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· ·. . , ,5tartlflg
Spa;k fLug .
.; \
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j\~·i.-t Motor
;c··· · '., • "'J.'J..- •.'" .
. . " OJIP ..""..L
ContaCt Breaker A.C OYllama "t.,
~.. :;_:_1: .:r::~.;;..._ . ~! /!t)~~~:') ":'f- rlr
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@ --'Green ' ® --' Orange ®--'Red
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":f.~4:,~. ::~,~~~~·'.i(j/'i'
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P. -- --•• - Pink
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Wire harness A.
Wire hnrnp.s<; B.
Va Ltage t2
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which is impossible to
2. CHARGING SYSTEM
followed
by
A.c.
Rotor-type
Generato r.
Frequently
The principle of generation of electricity by Rotor-type A.C. Generator is same as
Magnetic nux . in the iron core of
coil
turn
its
that
direction
much ' times as number of magnetic pole for each a turn of the magnetic iron.
as
For each
For
the
battery
ignition
system,
I't
" Impossi b Ie
IS
kicking even after perfect discharging of b aery
tt
d ue
A.c.
spark unless replaCing battery or
to
.ItS
A.c.
cycles (3 cycles per one turn for 6 poles Generatorl, so there generates
A .C.
voltage
of
magnetic
t
.
.
ua e Circuit connection.
in the generating coil due to this variation of magnetic nux.
The more magnetic force of magnetic iron , and the earlier rate of change
nux in the core Ithe more quick the rotation of magnetic iron, and the more number of
magnetic polesl and also the more number of winding of
coil ,
the
large
A.C.
voltage
is generated IFig. 11 -22, 11-241.
All these conditions couldn't be satisfied from
viewpoint
of
manufacturing,
magnetic for ce of magnetic iron, number of magnetic poles and
number
coil there is such inter relation as to increase one sacrificing other.
A.C.
Generator (Flywheel,
generating
wrong voltage variation and not equipped with
a
and
among
of winding
of
Due to defects of
coil of Generatorl, which works with
voltage
regu la tor, ' there
occur
much raise or drop of voltage if take the loading a t random not using regular
too
loading.
CD
®
®
Coil
A; Generato r
Fi xed core (iron CO r e and coill
o Cronk shaft
Fig . 11 - 23.
But recently th ese defects have been overcome by magnets manufacturers' effort.
On the other hand for magnetic weakening of
magnetic
iron
preventive
measures
A.c.
Brown (common use)
Fig . 11 - 24.
Circuit diagram of
Ro to r-typ e A. C. Gene rator
A B
A point of excellence of Rotor-type A.C. Generator due to it simple
type
C onstruction of Roto r-type
A. C. Generator
Yellow lusua l usel
Wh ite Iday and nightl
have
been taken in the course of design. (Fig. 11-231
struction is almost no trouble and lack of wear parts.
CD
®
®
Rotor (magnetic iron)
and
Special feature
of
strange
using
con-
20
10
q
Rotor-
Generator combined with ignition coil is to make it possible emergency starting
4
5
J
2
OI-'-oOL-~~~,-3ow~OOO~W-~~~~~
__
~~
1000
2000
3000
4000
SODa
6000
7000
8 000
qOOO
/0000
CD
®
Battery vo ltage EB
Charging current ZB
Fig. 11 - 25 .-{a)
Fig . 11 - 22.
Roto r-typ e A. C. Generator
152
A;
Volt
B; Amp
C hara cteristics of Rotor-type A.C. Generator (daytime)
153
by
high
oad wh ere generated voltage
as ',t is through celenium rectifier.
Therefore it enables eme rgency starting by switching of adeq
2
featu re of steep and
Generator under l'lght I
be conducted to ignition coil in D.C. or
magnetic pole number
to
recharging, but for the Rotor-type A.C. Generator system it is still possible to spark
induction voltage of Rotor-type
a turn of the magnetic iron, as magnetic nux in the iron core changes with
Rotor-type
there
OCcurs perfect discharging carelessly from capacity Battery mounted on motor cycle, due
to itssmall capacity.
A. Rotor-type A. C. Generator
of the nywheel magnets.
be
\.
A 8.
and spacers of requ ired number in series Or parallel and further acco rding
10
system it is set in comb-like arrangement on different rectifyi ng circuit style.
10
CD
q
15: ~
nickel plated circular Or rectangular form, refined selenium mixed with a adequate amo unt
of impurity is spattered in vacuum a nd further ready fusable alloy of Cd,
Bi
J
Sn
is
Then it becomes possible to get such phenomenon as current is easy to flow to positive
5
2
direction and al most shut to flow to another direction if put current to the reverse di rec-
ol~~--~~~~;;~~~--~~--~~--~6~o~oOO--;7~0;OO'--'8~ooo.o,--q~0~O~O--~I~O~OOO
o
/000
CD
o
200 0
.3000
40 00
tion to that shown by arrow.
SOOO
Th is is called re ctifying action of selenium rec ti fyin g plate.
This ch aracteristics caused by unsymmetric conductivity due
A; Volt
B; Amp
Battery voltage EB
Charging cu rr ent ZB
Fig. 11 -25.-(b)
to
the
layer of
th e contacting surface between pole and metal selen ium of sem i condu ctiv ity.
. is very harmful effect On the selenium rectifying plate,
C haracteristics of Rotor-type A.C. Generator (during night!
unti-moi sture processing
is connected in bridge a nd number of selenium
A.c.
current, always
R
A C Gene rat or or AC generating cod.
combined with oto r-type
. .
f
h.
fner but th e prin,
There are several kind s of construction, mate ria l and form or t IS rec I
. I Choro cter of easy flow of current t a one directi o n
is some uti li zing its speclo
.
C
generally used are celenlum
Types of rectiller
rectifi er, a nd germanium re ctifi er.
shown is Fig. 11-26101,
Rectifying un ·,t to
rectify
by
rec t·ce
III r,
rectifying
plate
becomes
ignition coil works for both cycles of positive and negative loading.
done
77
CB72,
much
and
Durability
the
of the
selenium rectifier depends on temperature largely; and it is prohibitted to ra ise mare than
30°C.
So is requested not to fl ow ove r current for a longtime.
and
d
copper .naxi .e
th e selenium
is
by moisture resistant point to prevent corrosion.
B. Celenlum rectifier
from. the
The celenium rec tin er is used for rec ti·f·
ylng th e Decurrent
..
barrier on
As moistu re
Th e selenium rectifying unit whic h is common fo r Model C72 , 77 a nd Model
closing to a th er.
Or
pured on its su rface to make electric pole after perfect heat treatment to make it active
metal selenium .
5
4
C·,ple
rectifying
Rectifying plate is shown in Fig. IAI, where on the base steel sheet Or alminium plate of
6
10
to
recti ler
CD
IS
®
and is composite d by rec tifying plates combined with end pla tes
I
®
@
A
CD
®
All wave rect ifier
Generating co il
@ A. C. voltage
@) D. C.
(AI
®
®
Rectify ing pla te
Insulating membrane
CD
o Electric pole
o Selenium
CD
®
+®•
Base pl~te (nickel plated steel o r
A sign of rect ifier o r rectifying plate
®
Fig . 11 - 26. - (b)
Positive dire cti on
a luminuml
IBI
Direction of cu:- re nt
On the other hand, there is so -ca lled resis ting reverse
area .
154
voltage which
mare
voltage
is
put to rever se d irect ion there OCCurs puncture IHere punctured part turns to be insula ting
substance at once and th is damage self-restores
Fig . 11 - 26. - (0)
Battery
Loading
its
function
reducin g
effective
rectifing
The mare number of puncture, th e more rectifying effiCiency will be decreased to
155
be overheatedl.
Therefore it is
necessary
to
raise
total
resisting
putting required number of plates in series corresponding to
A.C.
reve rse
voltage
voltage
by
generated
by
the generato r coil.
In Fig. 11-26Ibl, put AC. voltage between terminals P.Q. of the generating coil as IAI ,
generates about 2. 1 Volt lin case of perfect
chargingl.
charge,
this will
be up
to
2 5V
.
during
For Model C72, 77 6 V is used and for Model CS72 , 77 12 V is used, connecting each
cell of each 3 piece or 6 piece b y connecting rod in series.
181 , ICi == 1 , 2 , 1, it is evident ICi is most suitable for high AC. voltage rectifier as the
reverse voltag e per one rectifying plate is smallest.
Generally speaking' is selenium recti-
fying system for use of automotive AC.
coil
generating
ICi > lSI> IAI is
the
order
b
a
to
select corresponding to voltage.
h
c --l-~..I
~
CD
Selenium rectifier oss'y
a; Red termina l
b; Brown termina l
c; Volt
d; Yellow
f
(B
terminal
Fig . 11 - 27.
0;
term inal
b;
c;
d;
e;
f;
g;
h;
pate
dil ute su lpluric acid
anode plate
terminal
ce lt
separator
cathode plate
Storoge battery
Fig . 11 - 26. - (c)
The pole plate is made of lead antimony Iattice painted w ith powder
Remarks:
paste state and dried.
Special pre caution is necessa ry in using selenium rectifier not to run engine under such condition as no
loading slote \fo r instance unloading stat eof batt ery during daytime or taking out state ye ll ow of fuseL
as high voltage generated by generating coi l under no load or light load condition a cts to the rever:.e
direction.
Th is leads to puncture trouble an d wil l damage the selen ium re clifie r if continued a long
time .
On the other hand, there occurs aging change in the selenium rectifier for a long term use increasing
internal resistan ce in the rectifier plate to decrease output voltage and to in crease temperature.
The largest cause of a ging change is temperatu re raise and at more than 70°C in the
rect ifier
th is
change occurs rapidly, the refore it is requi red to select coo l position to equip it.
used for a long time.
In such case, before using rais e voltage slowly dyring one hour
from
been
lower
voltage [about half of standard l to restore its function.
c.
Battery
All the battery for automotive use are lead storage
shown in the figure i.e. anode plate group and
battery
cathode
and
plate
its
group
construction
lone
is as
plate
more
than anode groupl are put together in turn inserting separator between a node & cathode
plates, and these combined plates are stored in the cell lebonite or stirol
model
with electrolysis solution.
un it
One unit as shown in th e figu re is
called
an
dipped
cell
oxide
in
in dark brown colo r is filled
up and for cathode plate gray porous sponge Ii ke lead is "lied.
There contains expand in
b
.
g su stance to prevent contracting solidification while in use as
for separator thOIn cypress sheet Irecently rubber sheet with fine holes
are usedl is used
d I
. .
or sythetic plates
, a n g,ass mat IS Inserted between ano d'IC p Iate a nd separator to prevent oxidation of separator and d ropp'lng su b stance of anodic action.
There OCcurs discharge when connected load
between
plate changes
gravity of dilute sulphuric ac id will
d
ecrease to
to
both
Ie a d
drop
terminals
su Ip hate,
terminal
f
b
attery, a nd
accordingly, specific
0
voltage.
This
rate
of
decrease of specific gravity is proportional to amount of discharge
.
sho
. F' I
approximately as
wn In Ig al. So it wl'll be d ete rmined amount of d' h
b
h k
ISC arge or rema ining amount
y c ec ing variation of spec,'o,c
" gravity if known th e .In l't'10 I spec illc
0
gravity (sg. at com~
plete charge 1. 260 and sg. at
complete discharge 1.1 01 . Specific gravity of dilute sulphuric acid varies with change of t
t
empera ure. If also depend on the kind of battery
but generally about 1,260 is selected with
If u
converting standa rd temperature 20°C.
p t current on the discharged b tt
.
h
.
.
a ery In t e directIon reversal to discharging,
SUlphate generated on both plates restore th eir
and
157
156
lead
For anodic plate, hard lead ox·Ide
gradually substance of both po',e
The re is such tendency as to increase current to reverse direction if selenium reclifier has not
of
original
state,
·'.e.
become
lead
lead
oxide
and sponge, lead again, and specinc gravity of dilute
sulphuric acid
increase
be poured in and seal tightly " pouring orince.
gradually
yet is to be used ,initial charging is necessary.
and increase terminal voltage as charging progress.
CDt ®
,.,, '"
el' ~
,
.,•"
0
0
uo
Ql
..
1.16
It is required the initial charging should be done perfectly, otherwise this battery will
not display its volume 100% for future use and its life be shorten seriously .
~l'
""""
Precautio n necessary before starting for use;
1.0'
@
@
I'
®,
11
t-.....
®
t'--...
"
" 100
@
t-.....
"
80
Inspection should be done before use of Battery nn'sh
I ed .Inl't'10 I Charging as follow,
CD
®
®
"": ,~
"
60
40
®
<1l
~,<1l
®
20
Voltage
Specific gravity
Discharge limit voltage
Hours of discharging current
End of discharging
COmplete charge
Total discharge
Amount of charge
III Inspect if there is something unusual or not, as damage, happens sometimes during
transportation .
Especially due to damage on the case
there
happens
leakage
of
solution.
121 Peep inside through pouring port a ft er t a k'Ing cap, or check the level of solution
to be on regular height.
-@
Fig. 11- 28.
continuously
to attain both pole plates a perfect charging state for the nrst time.
®
,1.12
Th is is done after pouring electrolysis
solution charging with regular initial charging current for about 70 hrs.
(a) Discharge characteristics
under constant current
~
Therefore when battery not charged
If its level is lower, check damage if any on the case.
If no damage, supplemen t dilute su Iph
' aCI'd a f same spec inc gravity with other.
UriC
cell.
Eattery
131 If time elapsed more than two weeks after the initial charging, it is necessary to
01
Volume and rate of discharge Irate of chargingl
supplement charge to supply amount of self discharged electricity while let alone.
Volume of battery is denned as amount of volume dischargeable down to
end voltag e at terminals regulated by JIS from complete charged battery
discharge
During this supplement charging, it I's d eSlra
. bl e to c hec k level of solution to adiust
discharging
regular height and further measure and
To express its value
under constant current. Imean value 1.575 V per each unit celli
ke ep
recor d
af
va Itage,
specinc
gravity
Clnd temperature for each cell for future reference.
Ampere hour IAhl Idischarging current times discharging hoursl is used.
Volume of battery depends on temperature of discharging current and specinc gravity.
As conditions of volumes test regulated by JIS for use of battery
for
motor
cycle,
speCific gravity of electrolysis solution should be 1,260+0,005 Iconverted to 20 °CJ,
current 1.0 hours rate, and temperature of
discharge, given here the battery
solution
completely
25 + 2°C.
charged,
Concerning
discharge
down
rate
to
of
the end
discharge voltage with X ampere within T hours, volume of this battery is
expressed
by XT ampere-hours IAhl, and X ampere is called the
discharge
current
of
rate
of
of T hours.
Therefore battery of 10 hours rate volume II Ah
means
such
capacity
as
to dis-
charge 10 hours down to the end discharge volt and current of
10 hours rate of
discharge is II A.
10 hours rate of
charging.
Similarly for charging current, it is
expressed
To express amount of charging or discharging
current,
duration
of
Fig. 11- 29.
time
in hours down to the end discharging volt .is used.
Precautio ns wh il e in use ,'
II
bl
Supplement charging of Battery
Initial charging
Inspect battery periodically, once a week for automotive
use.
month or after each I 000-2000 km running.
Battery can be stored after assembly for a fairy long time, if not electrolysis solution
159
158
At
least
twice
a
For the battery, MBJ4- 12 type IVoltage 12 V,
the
21
level
of
Special atten tion should be paid on
t
Ina content of
distilled wate r or drinking wa er
of battery is transparent there is shown level of
sol~tion. and if short supply
metal. as
Ferrousl.
If
the
solution, but generally the
applied.
case
31
If used
for
a
long
.
t,me
.,n
',nsuff,'c',ent
charged
',II be accelerated and at lost it invites such difstate trouble called sulphation W
Such
original substance b y usua I c harg''ng .
flculty as to make it hard to restore
the other hand , if used with thin solution due
pole plate warps easy to short. On
Therefore it is requested to suppleto over discha rging separator gets damage.
ment change before the discharge limit. IFig.
11-29 ~ 11-311.
Duration of battery is expressed by hou rs fr om
while in stationary state.
If the pole plate
Keep always in charge d sta te.
10
shorten so much.
Therefore if t he
loading
hours
the
state to the complete discharged state using electricity for
height
be a d lusted about 13 mm over the separator.
of solution shou Id
'd fan on the plate
ir due to drop of level. there occurs ox, 0'
be exposed in the a
ad which decrease volume of battery, and effect the per.
making white sulphuric le .
f .
h t ng
So many troubles
formance of exposed plate to be serious couse a ,nner s or' .
therefore it wouldn't be ' exaggeration to soy
are experienced due to this couse,
shorten it life.
that is the must po rt of causes to
volume
rate
10 A hl
comple te
charging
each
separate
loading
overlapped
duration
will
M ean consu mpt ion
of cu rr ent
Standard
Head light
35/35 W
Cell moto r
0.4 kW
10
~
duration of ba ttery
(approximatel
3A
2 hrs
50 A
listed On othe r part
3. 5 A
Magnet ic starter switch
3W
Neutra l lamp
"
0. 25 A
40 hrs
lA
10 hrs
0.35 A
30 hrs
10WX2
Winker lamp
Tail light
4W
Stop light
8W
0.7 A
Speed meter lamp
3W
0.25 A
40 hrs
3.5 A
1.6 hrs
*
Stop
Ignition
0.8
Running -
~
* In
will
be about
Simultaneously
the
2 hrs.
total
1.2 A
1.5
100 P
H o rn
ins tances, if
be
This relation could be presumed from the following table .
Kinds of loading on ba ttery
For
is
case of Point closed and switch
6hrs
On
light 35 W is on, consumption is 3A on ly and duration
head
the
toil
lamp
consumption
will
be
but
A
if
10.35AI
6 .85A.
and ignition 13.5AI were
From
the
figure
above
used
shown
duration becomes 35 ~ 40 minutes.
While in runn ing, charging is done corresponding to engine revolution, so that riiffer ence between charging and discharging current will behove
charging
or
discharging.
Charging curren t >discha rging current
Fig . 11 - 30 .
Sign of leve l of solut ion
->charge battery
Charging current
< discharging
current
->discharge battery
Especially as large current nows while in use of cell motor, it is required to control
less than 5 seconds for one action. after that tokes rest
10 ~ 15 sec to repeat next
action .
There occurs rapid drop of voltage if large current token out
from
the
battery but
it restores the origina l voltage if taken a rest.
Therefore continuous pushing on the Cell Button causes voltage drop
preventing
storation to the effec t of early exhaus tion.
Fig . 11 - 3 1 .
Preca uti o n for us e
161
160
,
re-
L
2'
",
CD
.... 1
®
: ouPCD
J
®
L
8
l'
'"
Starter switch
Combination switch
Starting molor
@
Starting motor cable
®
Starter magnetic switch
®
Starter battery cable
(J) Battery
,
] ' Black red spiral
,
2' Yellow red spiral
{AI; Discharge current
{HI
8
9
i
Fig . 11 - 34.
Wi ring of Cel l starter
Duration
10
-'"
Fig . 11 - 32.
Relation between discharge current and duration
for MBJ 4·12 type {12 V. 10 AHI battery.
r-----
,
I
6'
I
CD:
I
I
I
3'
,
L
6'
3'
~
I
I
, - -@
I
-j~
L
l'
Fig. 11 - 33.
Selenium recti~er
2'
3'
4'
5'
6'
7'
Dark brown
Dynamo
Battery
Fuse connector
Fu se 15 A
I ' Red
r
I
I
CD
®
®
ill
®
. ilif~~7
Yellow
While
Black
White red spiro I
Earth to Frome
Charging current circuit diagram.
fig. 11 - 35.
D. Cell Starter
01
Slarting Circuit
The
starter switch of push botton style is equipped on the right side of the handle.
Starter motor
CD
®
®
Brush
Brush spring
Field coil
@
Pole core
@ Gear housing
®
®
Terminal
@
@l
Internal gear
(J)
Ball bearing
®
Sprocket shaft
®
Sprocket
@ York
Planetary gear
Center bearing holder
®
Armature
@ Cover band
@ Comutator
@ Comutator end
@ Bearing bush
frame
Pushing it, the starter magnetic switch is operated to feed current of about lOOA to
the starting motor from the battery for Model C 7 2. 77. and about 60A for Model
bl
CB 72. 77 to rotate the starting motor.
The starting motor is equipped in
front of
the
crank
case and
the
cronk
shaft
rotated by starting chain through the overrunning clutch from the dinamo side.
162
is
Reduction of starter
To gel
tion
required torque and revolution to rotate the cronk shaft by reducing revolu·
of th
e motor mechanical reduction is necessary. To complete this in high
163
weight ,the
.d
.
re uctlon
primary
done by planetary gear and further the secondary
I'S
reduction by starting chain.
5,78, 1 Iplanetary gear!
Primary reduction ratio
Secondary
the
starting
<D
®
®
1691 , 1
Total reduction ratio
As
)
2 , 77 ,1 !chainl
motor does not run
Pla net gear
Motor shaft
Internal gear
@ Sprocket shaft
constantly
there
seldom
occurs wear
but to
®
Sprocket
prevent moisture its construction is closed type .
Therefore after each 5,000 -1 0,000 km run the following
points
Fi g. 11 -3 8 .
should be checked
Reduction mechanism
with care.
CD
Check wearing on carbon brush and commutator.
were
®
®
Eliminaate carbon powder Iblow of! by compressed air!.
starting sprocket should be combined before reassemble t he starting motor.
Supply grease in the gear case.
If the sprocket were set in, without disassemblying the starting motor by mistake there
If required
by any
reason
to
take
out
the
taken
out
it
is
necessary
to
disassemble even
the
planetary gear and
happens rolation impossible due to hitting againsts the case by the
starting chair, do not disassemble the
planetary
the
gear,
(Fig. 11-36 - 11-381
slarting sprocket from the motor.
By any chance if the starting sprocket were token out it is necessary to
disassemble
cl
Dismounting the Starting Motor
a.
Take of! the slarting motor coble from terminal.
b.
Loosen
two
each
screws
of 6 mm
tightening
the slarting
sprocket cover
and
take of! the cover.
Q ex
CD
\l
c.
Loosen
two
screws of 5 mm on the starting motor side cove r and toke of! the
side cove r.
CD
®
Inte rna l gear
Planet gear
® Sprocket shaft
@ Sprocket
O~®
d.
While
starling
loosening
motor
4 bolts of 6 mm filled on the cronk case
from
the engine case, it wi ll be seperated
moving the starting sprocket from the chain.
fig . 11 - 36.
fig , 11 - 39,
f 'Ig. 11 - 37 ,
Cel l-motor attached on Engine
165
164
(F ig. 11-391
and
from
taking
out
the
engine by
re-
1. If turns the starting motor
E. Maintenance of the Starting Motor.
a . When the starting chain is pulled along the direction of arrow as shown
1.
Removal of the carbon brush.
a.
b.
Loose 2 bolts fitted on the commutator end frame and take it aut.
c.
By
taking
th e
the
picture.
Take off the cover band complete of the commutator.
au t
in
ca rbon
brush
pressing
spring,
b.
take
out
the
By rotating the sprocket, the clutch outer is turned when the roller is joined with
the starting sprocket and the clutch outer moving to the narrower side. Accordingly
carbon brush
the dynamo rotor is turned which is fixed with the clutchouter as one unit.
loosening the connecting screw a f the field coil and carbon brush.
c.
On
the
rotor
is fixed
on the crankshaft by a key
of
4 mm.
rotation
of the
clutch outer is transmitted on the crankshaft.
d.
Th e starting clutch roller spring is usefu l for smooth running of roller without any
irregular meshing.
A.
C!)
Mica piece
®
®
Commutator ICul
Motor shaft
Furthermore a
2.
cap is used to make smooth motions of the starting clutch
roller spring and the roller.
B.
3
2.
F·Ig . 11 - 40 .
spring
When the engine starts runnin g
Cross se cti on ·of commutator
Commutator
Th e commutator is as shown in Fig. IAI while in use copper pant get wear
to
turn
a.
Rotational spped of th e crankshaft becomes faster than that of th e sprocket.
b.
Transmission from the starting motor is cut, due to centrifugal force on the roller
which presses the spring and moves to the wider space of the clutch outer-
like IBI.
In such cases its is reguested to adjusts to be IAI.
a s this adlustment requires
h
It is advisable to rely on specia Iist sops
lunder cutting of mical
highiy
technics.
IFig. 11-401
Fig . 11 - 42. Picture showing principle of function
of th e overrunning dutch (AI
C!) A.c.
®
®
Fi g. 11 - 41.
F.
Generator rotor
Starting clutch-outer
10.2X 11.5 roller
Generator srotor and torting clutch
Over ru nning clutch
This transmit
rotation from the starting motor to the crank shaft, but reversaly from
the crank shaft can not rotate th e starting motor.
This construction is quite same with Model C72 .
IFig. 11 -4 1I
Fig. 11 - 43. Picture showing principle of function
of the overrunning clutch !B)
167
166
F. Starter magnetic · switch
3.
Lubri catlon
Current to rotate the starting motor will reach about 100
by oil dropped through the hall (AI
Lubrications for the ov er running clutch is done
IBI and starys inside of
in the Figure which passes through the groove at thre e parts
wire is needed, and als6 th e switch to make on or off should be larger size at the con-
the
01'1
inner
real
2035
of 20 mm
bush
and
tacting part.
th e lock oil seal 326575 to prevent
c Ieon
'1 his (A I and IBI by com aloe
place
at the
as
resistance
easy
most
between the battery and the starting motor and put the switch to
pressed air .
to
big
operate
convenient
operate
place
this magneto
separately to make possible remote control with least current.
1.
Precuation a bout Maintenance
of the over running clutch depends on the function of roller, special
atten-
Principle of function
01
If current nows on the primary side, an
electromagnet
actuates
to
attract
iron
core resist in g spring force.
tion is needed for i ts handling .
silicon
esignated one. (Part No. 719111.
grease put on the roller shou ld be used d
01
such
In such cases, switch utilizing magneto can be equipped
afte r disassembly it is necessary to
Therefare
As L ife
nnd
To reduce
switch feeding current directly on the starting motor.
burning .
4.
Accordingly it will be difficult to
A
bl
The contact point at the end of the iron
core
connects
the
secondary
circuit.
IFig. 11-461.
greasel
.
high resistant to cold and hot
This designated grease have seve ral features, Ie,
IClen ts due to temperature and
1_40°C ~ 200°Cl, least variation for frictions coe ff ··
other variation.
Before
up,
b.
'.
putting
this
grease
on, cleanse eac h par t by gasoline, and after drying
paint grease thinly all over the surface of the roller.
f 1 bout magnetic force.
Be care u a
.
No t only roller or roller spring,
avoided from
magnetizinz.
Any
b t
u
timy
also
parts
resistance
around
WI'11
the clutch should be
.
un f avora bly
affect
smouth
Fig. 11 - 45 .
running of roller.
\
\
\
\
\
CD
®
Quantity
Part name
N o.
Quantity
Part name
No .
Starter magnetic switch
Magnet coi l (primary coill
C ontact (ope rating side)
®
Terminal
1
Starting chain
1
8
Cross hole screw
3
@
Contact (Fixed side,
2
Starting sprocket
1
9
Half moon key lIargel
1
Ro ll er
3
10
R-crank shaft
1
Contact retu rn spring
Return spring
3
®
®
CD
4
Clutch outer
1
11
Bush
1
12
20305 oi l seal
1
13
326275 lock oil sea l
1
14
R cro nk bearing housing
1
15
Z bearing
1
5
Starling clutch roller
spring cup
Secondary side)
Fig . 11 - 46 .
3
6
Starting clutch roller
spring
3
7
AC dynamo ro tor
1
2.
Construction of starter magnetic switch
Precaution
0 1 When put voltage of 12 V between both terminal of th e primary ci rcuit, if heard
clucking sound , the contact point of the primary circuit is connected.
169
168
Moving core
b)
If uged for a long time, contact point gets wear and damage
to ' increase
resis-
is heard, sometance, and sometimes no current nows. leven if sound of clucking
times the cell motor forced to stopl.
In such
.
w ,' th a file or a sand paper .
the contact pOint
cases, disassemble it and
To disassemble take
this
c.
Spe edme te r, Tachome te r
polish
switch
For Model C 72, 7 7 is equipped only a speedmeter but not a tachometer.
The speedmeter is generally magnetic
from the body.
Operational
3. PARTS FOR USE OF SAFE GUARD
type,
and
rotation
proportional
to
that
of
the
wheel is transmitted to the speedmeter by means of a nexible cable.
current
on
the
primary
side
less
than
12 V, 3.5 A,
11-48)
IFig. 11-4 7,
For the
tachometer, magnetic tachometer is used
alike the speedmeter and rotation pro-
portional to that of the camshaft in the cylinder head is transmitted to the tachometer."
IFig, 11-491,
Fig. 11 - 47 .
D isassembly of magnetic switch (cap is opened)
Fig . 11 - 49 .
Speedo-fachometer
~--------------~~ \~.--~
0.0.
ri
'~
0
I\IO@~OO ""
WJ
--,",-Fi g . 1 1- 4 8 .
Disassembly of magnetic switch (assemb le part}
Fi g. 11 - 50 .
Dia l of Speedo-tachometer
The speedmeter is consisted of speed indicator and distance meter, and speed is expressed .
by km / h, and running distance is integrated up to 99.999 km by the distance meter.
The
tachometer
shows
revo lution number per minute by indicator Ir.p.m).
Construction-
ally it is same type with speedmeter and stared in the same case of the speedmeter.
Only different points are that no integration mechanism and different
on the dial plate.
171
170
sign
and
measures
-'V
,."
•
.
\
By meanS of thi s eddy current the mag net shelter disk is moved by proportional revolving
Construction of the speedmeter
The magnets rotates with some
and tachom eter is shown in the figure.
rc;tational speed with that of the Oexible
coble
and
the
induction disk lof aluminum or Copper model moves with indicator os one unit.
rnishes magnetic field
The magnet shelter d is k fu
to generate eddy current on the disk by
the rotatin g magnet.
force to the magnet and indicator shows on the dial balancing with reacti on of the correctly
adjusted ha ir spring.
W hen the can is stopped, Ion the tach ometer. engine is stopped I the indicator and the
induction disk come bock to the zero by restoring force of the ha ir spring.
Fo r
the
speed meter revolution of the front wheel is reduced in ther gear box, and
cob le turns 1400 revolut ions per
1 km run ning, on the
other
hand for
th e
the
tachom eter.
revolution of the com shaft is reduced further.
<D
®
®
Induction dish a xi s
Total distance meter
Indicator
@)
Hair spring
®
Magnet shelte r disk
(charcoal diskl
Induction disk
Magneto
®
(1)
Fig. 11 - 51.
Reduction ratio of the tachometer a xis to the cronk shaft is 3,20. IFig. 11-521.
Dial
reduction
JIS Regulation
flexible
. Shaft
Type
two 'o r
Principle of speedm eter
tri whee l car
4-wheel car
The distance meter
worm
on
it
is
tra nsmit
shown
reduction
rat io
Speed meier
indication
1 400
1/ 1 400
60 km / h
637
1/ 637
60 km/h
constructionally on
Fig. 11 -53, thie magnet shaft cutted
its rotati on as No. 2-->shaft N o. 3-->shaft No. 4-->wheel No. 5
wheel redUC ing each speed.
On
the
dial
of the
total
distance meter
figures as 0, I , 2 . . . 9 are marked. and
teeth are cut so a s to ro tate ;;ac h wheel for one turn, the succeeding wheel rotatis
revo lu tion.
Fig . 11 - 52.
' /10
IFig. 11-531.
Pa rts of Speedomete r
MEMO
<D
®
®
shaft
No.
shaft
:2
No.
No. 3 shaft
@) No . 4 shaft
® No. 5 · shaft
® Magneto
Fig . 1 1- 53.
(1)
Magneto shelter disk
®
Indication disk
®
Total
Construction of total distance meter
~...
..... ,
173
172
--
.- ....
...~~..,
TROUBLE SHOOTING
" . ~:
TROUBLE SHOOTING
~rocedures of diagnosis for finding out causes of trouble and their probable cauoes are
discribed as follows:
1.
Engine does not start or hard to start
111
Remove the carburetter float chamber and check for fuel flow, if fuel is not suppl ied
enough i
121
1-1.
Clogged fuel line
1-2.
Clogged fuel tonk cop vent hole
1-3.
Clogged fuel cock
1-4.
Clogged carburetter line or stuck needle volve
Remove the spark plugs. attach them to the spark plug cops, turn in the ignition
switch and rotate the cronk shaft with starter motor while the I -I elect rods are
grounded.
131
If the spark plugs do not spark well or nil;
2- 1.
Faulty spark plug, Ito make ' sure, check the spark plug with spark plug tester.1
2-2.
Sooty or wet spark plug
2- 3.
Contact breaker point
2-4.
Faulty condenser
2-5
Incorrect adiustment of contact breaker point
2-6.
Short circuit or breakage in ignition coil or wiring
2-7.
Damaged comCination switch
Check compression pressure at the cylinder with a compression gouge and if lock
or nil of compression is indicated in either cylinder
141
3-1.
Incorrect tappet clearance
3-2.
Incorrect seating of valves in valve seats
3-3.
Excessive wear in valve
3-4.
Excessive wear in piston ring , piston cylinder
3-5.
Blown out cylinder head gasket
3-6 .
Seized valve in valve guide ·
3-7.
Faulty valve timing
Start engine following
i
the procedure of starting but engine seems to start but
won't continue running i
4-1.
Too wide opened choke shutter in cold weather
4-2 .
W ide opened air screw of carburetter adiusting .air. screw
4-3 .
Damaged carburetter insulator Or gasket
177
"
2,
3,
Engine paes nat develope full power
Engine runs erratic and / or with miss firing
II I
II I
Stand
the
vehicle
an the main stand and rotate the rear whee l by hand w:,en
the charging gear is set in neut ra l, if wheel does not turn easil y;
121
131
141
I-I.
Dragging rear brake -incorrect adjustment
1-2.
Damaged whee l bea ring
1-3 .
Too tigh t dri ve chain t ension, in co rrect adjustment
Check th e clutch for slip and if it is found sl ippi ng;
Im proper adjustment of clutch
3-2.
Worn clutch fac ing
3-3 .
Weakened clutch springs
121
Measure the highest rev o luti ons of cran kshaft with a revolution coullter and if the
engine does not d evelope full revolution;
lSI
4_
4- 1.
Choked carbur etler at somewhere
4- 2.
Clogged air cl eaner
4- 3.
Insufficien t su pply of fuel to the intake
4- 4.
Clogged muffle r
4- 5.
Faulty ig nition coil or contact breaker points
4-6 .
Faulty seating of valve
4-7 .
Incorrec t ignition timi ng
4-8 .
Excess weak va lve springs
4-9.
Fau l ty spark plug; test the spark plug with spark plug tester
Check
oil
level
Damaged corbur etter insulator Or pac king
1-3.
Fault y spark plug
1-4.
Fa ulty condenser
1-6.
Fau lt y contact breake r point
1-7.
Incorrect tappet clearan ce
Che ck for missing at high speed and if the engine ,'s t'l l
s, un d er the same.
2-1 . Insufficient supply of fuel
2-2.
Incorrect valve timing
2-3.
Damaged or weak valve springs
2-4.
Other causes mentioned in No. II I
Excessive 0''I consum p tion or exh au st blue or black smoke
II I If the eng .ine ex hous ts smok e while con tinu ous
running at high or low RPM.
I -I. Worn cylind e r or piston rings
121
1-2.
Reve rs ely assembled ri ngs in piston
1-3.
Excess clearance between exhaust valve and guid e
If the engine exh aus t s sma ke just after when clos,'ng h
t ro tt Ie valve sudden ly from
ce rta in opening i
in the cran kcase and adjust the level to th e speCificat ion, or
5.
2-1.
Excess clearance between inlet valve and guide
2-2.
Clogged air vent ho le Or plastic tube
Clutch jerks or engages un smoothl y
III
excess amount of oil re sult in th e tr ouble.
161
1-2.
1-5 . . Faulty ignition coi l
Check the ty re air pressure and innate to the specific amount.
3-1.
Adjust a ir screw of carburetter properly and still runs under same
Circ um stan ces.
I-I. Fa ulty ignit ion timing
If the machine moves a fT wit h jerking or the eng',ne sto
ps a t th e moment when
th e clutch engaged.
Inspect f or excess heating of engine and if found it same;
I-I.
Uneven tensions of clutch springs
6- 1.
Excess carbon deposit in combustion chamber
1-2.
Disto rt ed clutch plates or facings
6-2.
Inferior grad e of fuel is used
1-3.
Sticky move ment of clutch plate',n t he c Iutch outer
6-3 .
Slippe ry cl utch
6-4.
Le an a ir -f uel mixture; imp roper size of main ie! in carburetter
6-5.
Dirty cylinder and cylinder head
6,
Gear shifting does not operate correctl y
III
When the changing gea r does not engage.
I-I.
171
Worn notch on th e shift drum
Check for the engine de ve loping or knocking when i t submit to quick acce re ra 1-2. ' Stuck shift fork to the shift drum
ti on or successive running at high speed a nd if it is so;
The
probable causes
1-3.
Worn shift fo rk
are same as No. 161.
178
179
.
'. r,.
while running;
If th e gear jumps out
the gear shifter
2-l. Worn dogs on
or distorted shift fork
2-2. Worn
spring
2-3. Weakened shift drum stopper
(2)
121
/.
1-2.
Worn broke cam
1-3.
W o rn broke pedal shaft
1- 4
Broke shoe contaminated with oil or w at e r
1- 5.
Stuck broke coble or rea r broke link
1-6.
Lock of grease in broke com
Broke squeaks when applied.
Engine ru ns with unusu a l noise whe n the tappet clearances assumed correctly:
If knocking noise is heard from cylinder when accererating engine .
I) I
Excess clearance between cylinder a nd piston
1- 1.
12)
If chattering noise i s heard even if the com chain has been adjusted;
Excess worn com chain
2-2.
Excess worn com chain tensione r sp ring o r rolle r
heard from crank case.
When knocking noise is
big end
3- 1. Worn cronk shaft
bearing
3-2. Worn cronk shaft
131
Excess worn broke sh oe
2 -2 .
Contaminated surface of broke shoe
2-3.
Warped or pitted wall of broke drum
2-4.
Excess wear of broke panel spacer
MEMO
operating clu tch lever.
If the clutch incu res noise when
and clutch outer
be!ween the clutch plate
4-1. Exc ess clearance
center and clutch plate
between the clutch
clearance
Excess
4 -2 .
141
8.
2- 1.
2-1.
Trouble s in steering
If it is felt that the steering is hard at turning;
111
121
9.
1- 1.
Ove r. tight st eering boll race s
1-2.
Da maged steering
1-3.
Bent steering stem
Stee rin g wonders or pu ll to one side while running.
2-1.
Worn fr ont and / or r ear wheel bearing
2 -2.
Distorted front and / or rear wheel rim
2-3 .
2-4.
Loosen spokes
Worn rear fork pivot bushing or fr ont arm pivot bushing
2-5.
Bent front fork or frame or rear fork
2-6.
Incorrect rear wheel alignment
3-7.
Uneven strength of cushion springs on both side
Troubl es of brakes
111
The
1- 1.
brak~
doe s not actuate properl y even after the free ploy is adjusted correctly.
Worn broke shoes
181
180