PIAGGIO (01 - 12)

C
ENGINE 500cc. 4T - 4V - H2O
4T
WORKSHOP MANUALS
1
05/04
INTRODUCTION
• All checks, maintenance, repairs or replacements of spare parts in the vehicles manufactured by Malaguti are to
be performed by skilled and expert technical personnel with specific experience in state-of-the-art technology and
full knowledge of the quickest and most rational procedures, technical characteristics, setting values and tightening
torques, information as to which may only be properly and exhaustively provided by the manufacturer.
• The present publication concerning four-stroke engines provides mechanics operating on Malaguti vehicles, whether
working out of authorised service centres or self-employed, the essential information for operating in accordance
with the latest Good Working Practices and Work Safety regulations.
• The present publication provides all necessary information for routine procedures on all the MALAGUTI motor
vehicles equipped with four-stroke engines currently in production at the date of issue. The information provided
deals with the “MOTORS” of the motor vehicle. Some basic technical information has been intentionally omitted as
it is considered to be common knowledge.
• Additional information is available in the SPARE PARTS CATALOGUES of each model.
• It is important that before referring to the specific motor-bike manual, the information given in this general section
be carefully read as it provides all the essential hints and guidelines for best consulting the various topics and main
technical subjects.
Note: the present manual provides the necessary information and instructions for the routine maintenance and
servicing of Malaguti scooter engines.
This information has been furnished to us by the engine manufacturers. Malaguti therefore declines all responsibility
for any error, omission or misrepresentation.
MALAGUTI reserves the right to make any changes and modifications hereto it deems necessary without prior
notice.
For further information and details, please contact Malaguti Servicing or Engineering Division.
MANUAL UPDATE
• The up-date pages of this publication will be delivered by us (in due course) already punched and therefore ready
for insertion in the Manual.
The superseded sheets should not be removed from the manual as they remain applicable to the servicing of premodified models.
• The table of contents will be duly updated in case of the insertion of new pages causing difficulty in the rational
consultation of the manual.
• IMPORTANT! The workshop manual is to be considered as an essential work instrument to be properly kept upto-date so as to maintain its “validity” over time.
NOTES FOR EASY CONSULTATION
Y
PAGE LAYOUT
X Engine model
Y Section (chapter)
X
W Page No.
Z Date of issue
MODIFIED PAGES
• Modified pages shall bear the same number as those in
the previous edition /pre-modified ones/ followed by the
letter M, with the date of issue appearing in the
appropriate box.
• Any modified illustrations shall bear the same numbers
as the pre-modified ones followed by a letter.
• The picture which has been given a negative number
(example F. 85 ), indicates that the previous numbers
have been intentionally omitted.
ADDITIONAL PAGES
• Any additional pages shall bear the last number of the
section to which they belong followed by the letter A
together with the date of issue.
2
W
05/04
Z
EDITING SYMBOLS:
• Symbols have been provided for quick and easy reference, identifying situations requiring utmost attention or
providing practical suggestions or simple information.
• These symbols may appear next to a text (in which case they refer solely to the text itself), next to a figure (in
which case they refer to the topic illustrated in the figure and to the relative text), or at the top of the page (in which
case they refer to all the topics dealt with in the page).
Note: The meaning of the symbols should be duly memorised as their scope is to avoid having to repeat basic
technical concepts or safety recommendations. They are therefore to be considered as veritable “memory tags”. In
case of any doubt as to their meaning, consult the page in which they are fully described.
CAUTION!
Recommendations and
precautions regarding rider
safety and motor vehicle
integrity.
MECHANICAL
MAINTENANCE. Operations
to be performed only by an
expert mechanic.
GAUGE
MEASUREMENTS
ELECTRICAL
MAINTENANCE.
Operations be performed
only by an expert electrical/
electronic technician.
SPARE PARTS
CATALOGUE. Indicates
information which may be
obtained by referring to said
catalogue.
CENTESIMAL
COMPARATOR
MEASUREMENTS
MICROMETER
MEASUREMENTS
Abbreviations
F
Cs
P
Pr
S
Sc
T
V
NO! Operations to be
absolutely avoided.
IMPORTANT!
BORE METER
MEASUREMENTS
Other symbols
Figure
Tightening torque
Page
Paragraph
Section
Diagram
Table
Screw
L
LOCTITE
N° ........
Molibdenum disulfite oil.
O
Note - The “operative symbols” refer to
assembling operations.
3
05/04
M
Engine oil.
S
Lithium-soap base grease.
P
Lithium-soap base grease.
NEW
Replace at each assembling.
GENERAL WORK PROCEDURES
• The advice, warnings and recommendations given hereafter are aimed at ensuring maximum work safety as well
as at considerably reducing the risk of accidents, personal injury, equipment damage and idle times, and should
therefore be strictly adhered to.
ADVICE
• Only use quality tools and equipment.
• Only use equipment conforming to EU Directives for lifting the vehicle.
• During operations, always keep tools and equipment at hand, possibly laying them out according to the sequence in
which they are to be used. Absolutely avoid putting them on the vehicle itself, out-of-sight or in poorly accessible
places.
• Always keep the work area neat and clean.
• When tightening screws or nuts, start with the larger diameter or inner fasteners, and tighten them in progressive
“pulls” using a “criss-cross” pattern.
• Preferably use open-end box wrenches by “pulling” and not “pushing”.
• Adjustable wrenches (F. 1) should preferably not be used as the movable jaw tends to open thus risking damaging or not
properly tightening the bolt to the correct torque. Use only in case of emergency, i.e. when a properly sized box wrench
is not available. In any case, when using an adjustable wrench, take care to proceed as shown in Figure 1.
F. 1
WARNINGS
• Before carrying out any operation, turn off the engine, remove the ignition key and wait for all parts to
cool down.
• For operations requiring two mechanics, make sure that the various steps to be performed by each of
them are clearly defined and co-ordinated beforehand.
• Make sure that each component has been properly mounted before proceeding with assembling the
next one.
• Lubricate all parts (where applicable) before reinstalling them.
• Always replace gaskets, O-rings, circlips and split pins at every refitting.
• The torque settings specified in the manuals refer to the “final torque”, which must be attained
progressively by steps.
• Loosen and tighten aluminium alloy parts (covers) only after the engine has fully cooled down.
• Only use screwdrivers with sizes suitable to the screws to be loosened or tightened.
• Make sure that the vehicle is stable and not to have to take on awkward working positions.
• Never reuse old gaskets or circlips.
• Never use a screwdriver as a lever or chisel.
• Never use pincers to loosen or tighten screws or nuts because, in addition to not providing a sufficient clamping
force, they may also damage the screw head or nut hexagon.
• Never tap the wrench with a hammer or other similar tool to loosen or tighten screws and nuts (F. 2).
• Never attempt to increase the lever arm by fitting a tube into the wrench (F. 3).
4
05/04
F. 2
F. 3
Never use open flames for any reason.
Never leave open containers or containers not suitable for holding fuel in passageways, close to heat sources,
etc.
Never use petrol to clean the vehicle or the floor of the workshop.
Always use low flash point solvents to clean the vehicle components.
Never suck from or blow into the fuel pipe.
When welding, make sure that there are no flammable liquids in the vicinity. Always remove the tank, even if
completely empty, and disconnect the negative cable (-) from the battery.
Never leave the engine running in closed or poorly ventilated areas.
Before any servicing, make sure that the motor-bike is perfectly stable.
The front wheel should preferably be anchored to the equipment integral with the lifting board.
ENGINE REMOVAL
• For removal of the engine from the frame, refer to the “cycle” shop manual which lists all the operations required.
ENGINE DISASSEMBLY
The manufacturer declines all responsibility for damage of any kind caused by disassembly and reassembly of
the engine and its parts if unsuitable tools ar used.
Only use ORIGINAL MALAGUTI SPARE PARTS.
5
05/04
500 cc
INDEX
S
CONTENTS
A
General characteristics
B
Special tools and torque wrench settings
P
8
9 - 10
Maintenance
C
Spark plug
Engine oil
12
Transmission oil
14
Timing inspection
15
Valve clearance inspection/adjustment
16
End of stroke compression pressure inspection
Automatic transmission
Cover
17
External air conveyor
Air conveyor filter
18
Air conveyor, transmission cover
Timing belt antiflapping roller
19
Driving pulley
Mobile driving semi-pulley
D
21
Clutch bell
Pipe pulley unit
22
Clutch disassembling
Pins check collar
23
Fixed driven half pulley ball bearings
Fixed driven half pulley
24
Mobile driven half pulley
Mobile driven half pulley spring
Clutch shoes
25
Driving belt
Final reduction
Reduction gear cap
26
Wheel axis and return shaft
E
Hub box ball bearings
27
Wheel axis ball bearing on the hub cover
Intermediate shaft bearing on the hub cover
Hub cover control
Hub shafts inspection
28
Flywheel cover
Coolant pump cap
29
Flywheel cover disassembling
F
“By-pass” flywheel cover components disassembling
Stator
Lamellar valve
31
Impeller
32
Flywheel and starting
Starter
G
34
Magneto flywheel
Freewheel
Components inspection
36
37
6
05/04
500 cc
S
CONTENTS
P
Thermal unit and timing system
Intake manifold
39
Tappet cover
Timing system control device
Camshaft and rocking levers
40
42
Camshaft inspection
43
Further controls
44
Head
Timing system components inspection
Valves
Cylinder
47
Piston
H
48
Pin inspection
Connecting rod small end inspection
49
Piston inspection
Gas rings
Cylinder base gasket selection
50
51
Head inspection
52
Cylinder inspection
Connections between piston and cylinder
53
Valves inspection
Valve clearance inspection
Valve seats wear inspection
54
Valves tightness test
55
Washers, cotters inspection
Springs inspection
Intake manifold
I
Injector
Throttle valve
56
Motor case and driving shaft
Motor case opening
58
Driving shaft removal
Countershaft removal
59
Notes on reassembling
Oil pump removal
60
Ball bearings replacement
L
61
Driving shaft controls
Driving shaft- case end float
Driving shaft - connecting rod axial space
62
Driving shaft concentricity inspection
Motor half casing inspection
63
Main bushing inspection
64
Countershaft control
65
Oil pump inspection
7
05/04
500 cc
MAIN
FEATURES
A
ENGINE
Type: ............................................................. 4-strokes
Number of cylinders: ................................................. 1
Bore: ................................................................. 92 mm
Stroke: ............................................................... 69 mm
Piston displacement: ....................................... 460 cm3
Compression ratio: ........................................... 10,5 : 1
Timing system: ........................ flywheel side chain
driven overhead
camshaft; three-arm
rocking lever with
threaded register.
Valves clearance : ................... suction:
0,15 mm. cold working
................................................ exhaust pipe:
0,15 mm. cold working
motor idling .............................. 1500 ± 50 g/min
air filter .................................... sponge, impregnated
with fuel mixture (50%
fuel and 50% oil).
CO Value %
Valore CO% (idling, warm) ............................... 1 ÷ 1,5%
Starting system ....................... Electric starter with
freewheel
Lubrication ............................... With pump (inside the
case)
Lubrication pressure ................ 4 bars
Minimum pressure allowed
(at 100° C) ........................................................ 0,8 bars
Supply ..................................... Electronic injection with
electrical fuel pump,
throttle valve Ø 38 mm
and single injector
Max. power allowed ................. 29 kW (39CV) at
7250 rev/min.
Max. torque allowed. ................ 40 N*m (4 Kg*m) at
5500 rev/min.
Cooling system ........................ with liquid, through a
pump operated by the
motor, three-way thermostat and electrical
fan.
8
Transmission ........................... automatic variator with
expanding pulleys, and
torque server, V belt,
automatic clutch,
reduction gear and
transmission space with
cooling system by
pump.
Motor oil .................................. ~ 1.7 litres (when dry)
~ 1.5 litres (when you
change oil and filter)
Rear hub ................................. ~ 250 cc.
Spark plug ............................. NGK CR7EKB
CHAMPION RG6YC
Generator ................................ alternate current, threephase generator
05/04
500 cc
Tool
B
SPECIALSPECIALI
TOOLS
ATTREZZI
Description
Notes
Code
Tool
Description
Notes
Code
001467Y002
001467Y007
Driven pulley
spring
compressor
001467Y009
Bell
N° 10
N° 17
001467Y010
020444Y
001467Y017
001467Y031
001467Y035
Pliers
20 mm
001467Y006
15 mm
001467Y014
18 mm
001467Y019
15 mm
001467Y034
Driving shaft
alignment
support
020074Y
Punch
020083Y
Pin
case
punch
Adapter
Guide
Handle for
adapters
Valve
cotters
removal
Roller case
assembling
punch, driven
pulley
Extractor for
valve oil
retainer
Oil pressure
manometer
union
Magnetic
base with
comparator
Adaptor
020478Y
32x35 mm
020357Y
37x40 mm
020358Y
42x47 mm
020359Y
52x55 mm
020360Y
28x30 mm
020375Y
12 mm
020362Y
15 mm
020412Y
17 mm
020439Y
20 mm
020363Y
25 mm
020364Y
30 mm
020483Y
020456Y
32x35 mm
020357Y
37 mm
020477Y
Flywheel
extractor
020467Y
Pin retainers
assembling
020470Y
Countershaft
timing pin
020471Y
Flywheel
Stop
020472Y
Driving
pulley
stop
020376Y
24 mm
020474Y009
Piston
position
inspection
020475Y
Countershaft
stop
020479Y
Piston
assembling
fork
020512Y
Flywheel
lock caliper
wrench
020565Y
Case
separation
plate
020262Y
020382Y
020424Y
020431Y
020434Y
020335Y
9
05/04
B
500 cc
TORQUE WRENCH SETTINGS
Particular
Q.ty
Torques (N*m)
Countershaft fastening nut
1
25 ÷ 29
Motor oil filter
1
12 ÷ 16
Motor oil drain plug
1
24 ÷ 30
Case connecting screws
14
11 ÷ 13
Gear screws on the driving shaft
4
10 ÷ 12
Oil pump compartment closure screws
2
8 ÷ 10
-
24 ÷ 27
Driven pulley nut
1
92 ÷ 100
Driving pulley nut
1
160 ÷ 175
Transmission cover fasteners M8
4
23 ÷ 26
Fastener M6
7
11 ÷ 13
Antiflapping roller fastening
1
17 ÷ 19
Clutch ring nut
1
65 ÷ 75
Internal air conveyor screws
2
7÷9
Water pump cover screws
6
3÷4
External transmission cover screws
4
7÷9
Flywheel cover screws
14
11 ÷ 13
Transmission oil drain plug cap
1
15 ÷ 17
Flywheel fastening nut
1
115 ÷ 125
Stator fasteners
3
8 ÷ 10
Blow-by recovery duct fastening screws
2
3÷4
Freewheel fastening screws on the flywheel
6
13 ÷ 15
Stator harness guide hanger screws
2
3÷4
Coolant pump impeller
1
4÷5
Oil pump connecting screws
2
0,7 ÷ 0,9
Oil pump fastening screws
2
5÷6
2
11 ÷ 13
DRIVING SHAFT CASE
FINAL REDUCTION
Hub cover screws
TRANSMISSION COVER
FLYWHEEL COVER
LUBRICATION
MOTOR UNIT
Starter fasteners
10
05/04
B
500 cc
TORQUE WRENCH SETTINGS
Particular
Q.ty
Torques (N*m)
Spark plug
1
12 ÷ 14
Head fastening stud bolts
4
***
Head fastening nuts
2
10 ÷ 12
Exhaust / intake head fastening nuts
2
10 ÷ 12
Head lubrication control jet
1
5÷7
Coolant temperature sensor
1
10 ÷ 12
Coolant temperature sensor
support nut
1
10 ÷ 12
Counterweight mass fastening screw
1
7 ÷ 8,5
Tightener shoe fastening screw
1
10 ÷ 14
Chain guide shoe retaining plate screws
3
3÷4
Stroke revolutions sensor fastening screw
1
3÷4
Injection fastening screw
1
3÷4
Valve lifter mass stopping bell fastening screw
1
30 ÷ 35
Intake manifold fastening screws
3
11 ÷ 13
Tappets cover fastening screws
6
7÷9
Throttle valve fastening screws
3
11 ÷ 13
Camshaft retaining brackets fastening screws
3
4÷6
Tightener fastening screws
2
11 ÷ 13
Tightener fastening central screw
1
5÷6
Head tightening screw
3
10 ÷ 12
Camshaft retaining brackets screws
3
4÷6
THERMAL UNIT AND TIMING SYSTEM
***
Operate first a torque wrench setting of 7 N*m in cross section sequence.
Tighten of 90° in cross section sequence.
Tighten again of 90° in cross section sequence.
11
05/04
500 cc
MAINTENANCE
SPARK PLUG
Inspection
each 1.000 Km
Replacement
each 12.000 Km
C
• Remove the spark plug while the engine is hot (taking
utmost care to avoid scalding!).
• The carbon deposits and the colour of the insulator
(around the central electrode) provide good information
as to the heat range of the spark plug and to
carburetion, lubrication and general condition of the
engine.
• A light brown colour of (the insulator) indicates that
engine working conditions are generally correct.
• Sooty black mat deposits, dry (to the touch), are a sign
that working temperature is too low, i.e., that the heat
range of the spark plug is too high, mixture too rich or
ignition defective.
• A whitish colour of the insulator is indicative of too lean
a mixture or of too low a heat range of the spark plug
(i.e., spark plug too “hot”).
• Check electrode gap (F. 4) (even if the spark plug is new)
by means of a calibrated thickness gauge. If need be,
adjust by acting only on the earth electrode.
Advised spark plug:
Cs - N*m
12 ÷ 14
F. 4
CHAMPION RG6YC
NGK CR7 EKB
ENGINE OIL
Level inspection
This operation has to be carried out when the motor
is cold, following the here reported instructions:
1) Position the vehicle on its central stand and on a level
ground.
2) Unscrew the dipstick/cap “A”, dry with a clean cloth
and reinsert it, tightening it.
3) Remove again the dipstick/cap and be sure that the
level is between the indexes “Max” and “Min” (F. 6);
top up, if necessary.
D
Cs - N*m
12 ÷ 16
A
The reference of the “MAX” level shows a quantity of
about 1700 cc of oil into the motor.
F. 5
D
Note - Should the control operations be carried out after
having used the vehicle, that is to say when the motor is
warm, the level line will be lower; in order to carry out a
correct inspection, it is necessary to wait for at least 10
minutes after having stopped the motor.
A
Oil top up
• The oil topping up, when necessary, should be carried
out after the level inspection and, in any case, add oil up
to the “Max” level; be sure never to pass this limit.
• The oil topping up from “Min” to “Max” requires about
400 cc.
F. 6
12
05/04
C
500 cc
Oil and oil filter change
B
Note - The engine oil has to be changed when the engine is warm.
• Remove the filler cap (A - F. 5).
• Drain the oil removing the drain (B - F. 7)
• Let that the oil flows into the appropriate container.
• Remove and clean the pre-filter (C - F. 9) with
compressed air.
• Remove the cartridge filter by means of a wrench for
filters (D - F. 5).
• Be sure that the O-rings (D - F. 9) of the pre-filter and
of the drain plug are in good condition.
• Lubricate them and install again the pre-filter and the
plug, tightening it to the specified torque.
• Install a new cartridge filter and do not forget to lubricate
the O-ring before the installation; screw to the gasket
contact point, tightening by hand.
• Pour the oil in the oil pan until it reaches the level
between MIN and MAX. (the plug B is screwed tight).
• Close the oil filler plug (A - F. 5).
• Start the engine in order to load the filter and the
lubrication system.
• Stop the engine and wait approx. 5 ÷ 10 minutes.
• Reset the level to the MAX level.
Oil used:
Cs - N*m
24 ÷ 30
F. 7
B
SBK RACING 15W - 50
F. 8
C
F. 9
13
05/04
D
C
500 cc
TRANSMISSION OIL
Level control
A
• Position the vehicle on a level ground and on its central
stand.
• Unscrew and extract the oil dipstick (A), dry it with a
clean cloth and reinsert it, tightening it.
• Extract again the dipstick, controlling that the oil level is
between the indexes of “MAX” and “MIN” on the dipstick
(F. 11); should the level be under the “MIN” notch, it will
be necessary to restore the right quantity of oil into the
hub.
• Screw again the dipstick, checking the tightening.
F. 10
A
F. 11
Oil replacement
• Remove the oil filler cap (A).
• Arrange for an adequate container.
• Unscrew the oil drain plug (B) and let that the oil flows
out completely.
• Screw again the oil drain plug with its relative gasket (C)
and supply new oil.
• Screw again the oil filler cap.
C
Oil used:
ZC90 - SAE 80W90
B
Prescribed oil quantity ~ 250 cc.
B
F. 12
F. 12/a
14
05/04
Cs - N*m
15 ÷ 17
C
500 cc
TIMING INSPECTION OF THE TIMING SYSTEM
• By means of a wrench, type TORX, remove the timing
inspection cap, positioned on the flywheel cover.
• Remove the transmission cover and the relative
soundproofing material.
• Rotate the driving shaft by means of the driving pulley,
so that the reference point on the magnet support
collimates with the one on the flywheel cover (PMS - F.
13).
F. 13
• Remove the head cover (F. 14).
F. 14
• Be sure that the reference point operated on the phonic
wheel is aligned with the one operated on the head.
Should the reference point be on the opposite side of
the reference point operated on the head, make the
driving shaft rotate once more.
F. 15
15
05/04
C
500 cc
VALVE CLEARANCE INSPECTION/ADJUSTMENT
This control has to be carried out when the motor
is cold.
B
• In order to carry out the inspection of the valves
clearance, it is necessary that the timing reference points
of the timing system collimate (see previous paragraph).
A
• Control, by means of a feeler gauge, that the clearance
between the valve and the register corresponds to the
indicated values. Should the values of the valve
clearance, intake and exhaust, be different from those
reported here following, proceed with their registration
by loosening the counter nut (A) and operating with a
screwdriver on the register (B).
Intake work: 0,15 mm
Exhaust work: 0,15 mm
F. 16
COMPRESSION END PRESSURE INSPECTION
This control has to be carried out when the motor is cold.
• Remove the spark plug cap.
• Remove the spark plug.
• Insert into the spark plug seat a compression gauge, by means of a 10 mm spark plug connector, at the right torque
wrench setting:
Connector to test compression: 10 N*m
• Disconnect the connector of the stroke revolutions sensor.
• Start the motor by means of the starter with the throttle valve fully opened, as long as the pressure gauge reading is
stable. If the pressure is higher than 8 ÷ 11 bars, remove the pressure gauge and proceed with the reassembling of
the spark plug, of the cap and of the stroke revolutions connector.
• When the pressure values are lower than those indicated, check the engine revolution number at which the test is
carried out; if lower than 450 rev/1', check the starting unit.
Should the revolution number be the correct one, or slightly higher, proceed as follows:
-
Check the timing of the timing system
Check the valve clearance
Check the valve seal
Check the piston ring seal
Check the correct selection of the compression rate (cylinder base gasket).
16
05/04
500 cc
AUTOMATIC
TRANSMISSION
D
COVER
A
• Unscrew the four screws (A).
• Remove the cap (B).
• Remove the plastic cover (C).
Cs - N*m
7÷9
A
B
C
F. 17
Cs - N*m
M6 11 ÷ 13
• Unscrew the seven screws (M6).
• Unscrew the four screws (M8).
• Unscrew the fastening nut (D) of the driven pulley shaft,
preventing the rotation of the shaft itself by means of a
socket hexagonal wrench.
Cs - N*m
M8 23 ÷ 26
M8
D
M6
F. 18
• Remove the nut (D), with the relative washers.
• Remove the transmission cover.
D
Cs - N*m
92 ÷ 100
F. 19
• Check that the transmission cover ball bearing rotates
freely; should this not be the case, replace it.
F. 20
17
05/04
D
500 cc
EXTERNAL AIR CONVEYOR
• Unscrew the four fastening screws of the external air
conveyor.
F. 21
• Remove the external air conveyor.
F. 22
AIR CONVEYOR FILTER
• Unscrew the two fastening screws and remove the air
conveyor filter (A).
A
F. 23
AIR CONVEYOR, TRANSMISSION COVER
B
• Unscrew the two screws (B) and remove the air conveyor
(C).
F. 24
18
05/04
C
B
Cs - N*m
7÷9
D
500 cc
TRANSMISSION TIMING BELT ANTIFLAPPING
ROLLER
B
A
• Control that the roller rotates freely (A) and that there
isn’t any sign of anomalous wear.
• If necessary, replace the roller with its bearing.
C
F. 25
V
• Unscrew the M8 screw (V).
• Remove the antiflapping roller (A).
V
Cs - N*m
17 ÷ 19
A
V
F. 26
DRIVING PULLEY
C
• By a 27 mm wrench, turn the nut (C), so that the inner
holes align horizontally, for the installation of the special
tool:
Cs - N*m
160 ÷ 175
code 020474Y009
• First insert the retaining ring of the tool on the pulley, so
that the slot (B - F. 25) fits well.
• Then insert the tool, so that the stud bolts on the ring fit
well with the holes on the tool itself.
• Tighten (manually) the two tool fastening nuts.
C
F. 27
• Unscrew the nut (C).
• Remove the plain washer and the cone-shaped washer.
• Remove the fixed driving half pulley.
C
F. 28
19
05/04
D
500 cc
• Remove the washer on the bush.
F. 29
• Move the driving belt.
• Hold up the disk on which are leaning the rollers and
extract the mobile driving semi-pulley with its relevant
bush.
Be careful not to cause the rollers discharging.
F. 30
• Extract the bush.
F. 31
• Remove the rear washer.
F. 32
20
05/04
D
500 cc
MOBILE DRIVING SEMI-PULLEY
B
• Inspect the bush inner diameter (A).
A
Ø standard : 30,021 mm
Ø max.
: 30,120 mm
• Inspect the pulley sliding bush (A) external diameter.
Ø standard : 29,959 mm
Ø min.
F. 33
: 29,950 mm
The rollers (B) have to be positioned as shown
in the picture. The covered part must turn out
to be the support on the inner pressure side of
the rollers container.
B
• Control that the rollers (B) are not damaged or
excessively worn.
Ø standard : 24,9 mm
Ø min.
: 24,5 mm
F. 34
• Control that the pads (C) of the plate (D) on which are
leaning the rollers are not worn.
• Control furthermore the state of use of the rollers housing
slots and the surfaces in contact with the driving belt,
on both semi-pulleys.
C
D
F. 35
21
05/04
D
500 cc
CLUTCH BELL
Removal
• Extract the spacer (A) and extract the clutch bell.
A
F. 36
B
Inspections
• Control that the clutch bell is not damaged or excessively
worn.
• Control the inner diameter (B) of the clutch bell.
B standard : 160,2 mm
B max.
: 160,5 mm
Maximum eccentricity value allowed: 0,2 mm.
F. 37
DRIVEN PULLEY UNIT
• Extract the driven pulley unit, transmission belt included.
F. 38
CLUTCH DISASSEMBLY
• In order to separate the clutch from the driven pulley, it
is essential to use the special tools.
Spring compressor - code 020444Y
F. 39
22
05/04
D
500 cc
• Prearrange the tool, with the median pins screwed in
position “E” (reference point on the tool), on the inner
side.
• Assemble the driven pulley unit on the tool, inserting
the pins into the ventilation holes.
• Operate so that the setscrew fits well with the fixed driven
pulley.
F. 40
The tool has to be correctly secured within a
vise and the central screw should be brought
into contact with the tool itself. Too high a value
of the torque may deform the special tool.
• By means of the specific 55 mm wrench, remove the
fastening ring nut (G); then, disassemble the clutch unit.
G
Cs - N*m
65 ÷ 75
55 mm wrench - code 020444Y009
F. 41
PINS RETAINING COLLAR
• Extract the collar, by using two screwdrivers.
F. 42
• Extract the four guiding pins.
• Extract the mobile driven half pulley.
P
F. 43
23
05/04
G
D
500 cc
FIXED DRIVEN HALF PULLEY BALL BEARINGS
•Verify the total absence of damages and excessive wear.
• Remove the stop ring, using adequate pliers.
A
Support the pulley adequately, in order not to
damage the thread.
F. 44
• By means of the special tool, inserted through the roller
bearing, expel the ball bearings.
Special tooling:
Handle - code 020376Y
Adapter 24 mm - code 020456Y
20 mm guide - code 020363Y
When replacing the bearings of a driven pulley
assembly, it is necessary to support as follows:
F. 45
Bell - code 001467Y002
• Overturn the pulley and, by means of the special tool, remove the roller bearing.
Special tooling:
Handle - code 020376Y
25 mm guide - code 020364Y
Adapter 28 x 30 mm - code 020375Y
Bell - code 001467Y002
FIXED DRIVEN HALF PULLEY
Inspections
• Control if there is any sign of wear on the contact surface of the transmission belt.
• Verify the external diameter (A - F. 44).
Ø standard : 49,965 mm
Ø min.
: 49,960 mm
FIXED DRIVEN HALF PULLEY
B
Inspections
MOBILE DRIVEN HALF PULLEY
Inspections
• Verify if there is any sign of anomalous wear on the contact
surface of the transmission belt.
• Remove the o-rings, internal and external ones.
• Measure the inner diameter (B) of the mobile half
pulley bush.
Ø B standard : 50,085 mm
Ø B max.
: 50,080 mm
The O-Rings are of two different sizes. The biggest
one is installed on the range of action at the base
of the half pulley.
24
05/04
F. 46
D
500 cc
SPRING OF THE MOBILE DRIVEN HALF PULLEY
• Measure the free length (L) of the spring.
“L” standard : 125,5 mm
“L” min.
: 120,0 mm
F. 47
CLUTCH SHOES
• Control the thickness of the frictional material (A) of the
clutch shoes.
Minimum thickness allowed: 1 mm.
A
A
F. 48
A
The clutch shoes should not present any trace
of lubricant. If any, accurately control the
tightness of the driven pulley unit.
During the running-in phase, the clutch shoes
have to be subjected to homogeneous wearing
(central contact surface). Different conditions
might cause the sliding of the clutch.
Do not open the clutch shoes with tools, in order
to avoid a loading variation of the return springs.
AA
F. 49
DRIVING BELT
Should the driving belt present any damages,
even the slightest one, replace it.
• Check the width (L) of the belt.
“L” standard : 26,2 mm
“L” min.
: 25,0 mm
F. 50
25
05/04
500 cc
FINAL REDUCTION
E
REDUCTION GEAR COVER
• Drain the oil from the rear hub, removing the cap
(T - F. 54) positioned on the lower part of the engine.
Use an appropriate container. Do not dispose of
the oil in the natural environment.
F. 51
• Unscrew the seven fastening screws (V - F. 54) of the
cover.
F. 52
• Remove the hub cover and the relative gasket.
F. 53
NEW
V
Cs - N*m
24 ÷ 27
V
T
F. 54
26
05/04
T
Cs - N*m
15 ÷ 17
E
500 cc
WHEEL AXIS AND RETURN SHAFT
• Remove the return shaft and the wheel axis, together
with its gear.
F. 55
HUB BOX BEARINGS
• Verify the condition of the bearings: smoothness
(anomalous frictions), noise during rotation, end plays.
• In case of malfunctions, replace the bearings by means
of the special tools.
• Be careful not to lose or forget the centring bushes (A).
• As far as the removal of the bearing (wheel axis) on the
engine case is concerned, use:
Pliers 15 mm - code 001467Y34
B
Bell - code 001467Y031
F. 56
A
• As far as the removal of the bearing (return shaft) on the engine case is concerned. use:
Pliers 20 mm - code 001467Y006
Bell - code 001467Y035
• As far as the removal of the bearing is concerned (driven pulley shaft), remove beforehand the Seeger ring (B).
• By means of the specific tools, remove the bearing of the driven pulley shaft from the engine case.
Handle for punch - code 020376Y
Adapter 37 ÷ 40 - code 020358Y
Guide 25 mm - code 020364Y
WHEEL AXIS BEARING ON THE HUB COVER
• Remove the Seeger ring from the external side of the
hub cover.
F. 57
27
05/04
E
500 cc
• Support the hub cover, by using a stud bolts kit.
• Remove the bearing by means of the special tooling:
Stud bolts Kit - code 020476Y
Handle - code 020376Y
Adapter 37 mm - code 020477Y
30 mm guide - code 020483Y
• Remove the oil retainer with a screwdriver (from the
external side of the cover).
F. 58
INTERMEDIATE SHAFT BEARING ON THE HUB COVER
• Support the hub cover, by using a stud bolts kit.
• Remove the bearing by means of the special tooling:
Stud bolts Kit - code 020476Y
Pliers - code 001467Y006
Bell - code 001467Y007
INSPECTION OF THE HUB COVER
• Control that the coupling surface is not deformed or dented. In case of anomalies, replace the hub cover.
HUB-SHAFTS CONTROL
1
• Verify that the three shafts are not excessively worn or
deformed on the threaded surfaces and on the ball
bearing/oil retainer coupling diameters (as shown by the
letters in the different points).
• In case of anomalies, replace the damaged parts.
1) Return shaft
2) Wheel axis
3) Driven pulley shaft.
2
F. 59
Capacity diameter for return shaft:
A = Ø 20
- 0,01
- 0,02
mm
Capacity diameter for wheel axis:
B = Ø 30
- 0,010
C = Ø 15
- 0,01
- 0,023
- 0,02
mm
mm
Capacity diameter for driven pulley shaft:
D = Ø 17
- 0,01
E = Ø 20
- 0,01
F = Ø 25
- 0,01
- 0,02
- 0,02
- 0,02
mm
mm
mm
F. 60
28
05/04
3
500 cc
FLYWHEEL
COVER
F
• Cut the clamps (A - B).
• Disconnect the two rubber sleeves, being careful not to
damage the connectors.
A
V6
F. 61
B
COOLANT PUMP CAP
• Unscrew the six fastening screws (V6) and remove the
cap of the coolant pump.
Cs - N*m
3÷4
V6
F. 62
Note - if necessary, it is possible to remove the pump
cap complete with its sleeves.
F. 63
HUB COVER DISASSEMBLING
• Prepare an appropriate container.
• Unscrew the motor oil drain cap (S).
S
F. 64
29
05/04
NEW
NEW
F
500 cc
• Extract the precleaner (A).
A
F. 65
• Unscrew and remove the motor oil filter cartridge (B),
using a filter wrench.
B
Cs - N*m
12 ÷ 16
F. 66
• Unscrew the 14 fastening screws (C) (the screws are of
4 different lengths. Take note of each position).
• Remove the flywheel cover with the relative gasket and
the support for the rubber sleeves.
C
B
NEW
C
Cs - N*m
11 ÷ 13
NEW
F. 67
30
05/04
F
500 cc
“BY-PASS” FLYWHEEL COVER COMPONENTS
DISASSEMBLING
• Remove the by-pass (A) and the spring (B).
• Verify the absence of damages or scorings on the outer
diameter of the by-pass (Ø 10,5 mm).
• Verify the free length of the spring (B):
standard
: 65,2 mm
min.
: 64,0 mm
A
B
F. 68
D
STATOR
• Unscrew the screws (V2) and remove the retaining bracket
(C) of the harness.
• Unscrew the screws (V3) and remove the stator (D), complete
with its harness.
Cs - N*m
3÷4
V2
Cs - N*m
8 ÷ 10
V3
Stator inspection
• Control the good condition of the stator and of the relative
harness.
• Verify the continuity among the three phases and the mass
insulation of each phase.
(Resistance of each phase: 0,2 ÷ 1 Ω).
• In case of anomalies, control the harness accurately.
F. 69
LAMELLAR VALVE
• Unscrew the two fastening screws and remove the support
of the lamellar valve with side wall.
F. 70
• Unscrew the fastening screw and extract the gas branch pipe,
with the relative O-Ring.
F. 71
31
05/04
V3
V2
C
F
500 cc
• Remove the blow-by lamellar valve, with its relative
sealing gasket.
F. 72
• Be sure that the blade of the blow-by circuit, closes
correctly.
F. 72/a
“WATER” PUMP IMPELLER
• Unscrew the coolant pump impeller from its relative shaft
and remove it.
A
Cs - N*m
4÷5
There is a right-hand thread. It is necessary to
prevent the rotation of the shaft, by inserting a
12 mm wrench in order to stop the shaft.
F. 73
• Extract the shaft with its relative washer.
M
F. 74
32
05/04
F
500 cc
• Verify that the coolant pump shaft does not present any
sign of anomalous wear.
F. 75
• Verify that the impeller of the pump does not present
any deformation or damage.
• Be sure that the plastic part is perfectly integral to the
metallic part.
F. 76
• Remove the sealing ring (pump impeller side).
F. 77
• Remove the ceramic ring and the relative seal.
In order to avoid damages to the ceramic seal,
carry out the assembling manually.
• Accurately verify the lubrication ducts: the three channels
of the by-pass, the water pump shaft oil feeding duct,
the pump drain pipe, the feeding duct of the oil pressure
sensor, the decantation chamber of the oil vapor.
F. 78
33
05/04
500 cc
FLYWHEEL AND
STARTING
G
• Control that the cover of the coolant pump does not
present any deformation or cracks.
Before repositioning the pump cover, replace
the O-Ring, paying attention that the latter does
not enter into contact with lubricating agents.
Note - Disassemble the flywheel cover as described in
the previous paragraphs.
NEW
F. 79
STARTER
Note - This operation can be carried out with the
flywheel cover assembled.
Cs - N*m
11 ÷ 13
V2
• Unscrew the fastening screws (V2) and extract the
whole starter.
V2
F. 80
MAGNETO FLYWHEEL
• Align the two holes on the magneto flywheel, with the
housing on the case (seat A), so that to allow the
insertion of the special tool:
Stopping flywheel device - code 020472Y
A
F. 81
• Screw the stopping flywheel device bush on the thread
destined to the extractor.
F. 82
34
05/04
G
500 cc
• Insert the special tool, paying attention that the pins are
inserted correctly into the holes previously aligned, on the
magneto flywheel.
B
Do not insert the device pin (B), into the bearing,
but be sure to insert it into the case seat (A - F. 81).
• Position the device correctly (it should be almost aligned with
the flywheel).
• Insert the wrench into the device and unscrew the fastening
nut of the magneto flywheel.
• Remove the special tool and the fastening nut.
Cs - N*m
Flywheel fastening nut
115 ÷ 125
F. 83
• Remove the washer.
F. 85
Cs - N*m
3÷4
V3
• Insert the specific extractor.
• With a wrench of 27 mm and one of 19 mm, unblock the
magneto flywheel and extract it.
Flywheel extractor - code 020467Y
• Unscrew the screws (V3) and remove the retaining plate
of the chain guide shoe.
V3
F. 86
35
05/04
G
500 cc
• Remove the key from its seat.
F. 87
• Remove the starting ring gear.
F. 88
S
• Extract the intermediate gear, provided with the torque
limiting device.
F. 89
FREEWHEEL
When disassembling the freewheel, it is
advisable to loosen beforehand the six
fastening screws, with the flywheel still
assembled on the driving shaft.
• Unscrew the screws (V6).
V6
Cs - N*m
13 ÷ 15
V6
L
243
F. 90
36
05/04
G
500 cc
The freewheel and the magneto flywheel are
closely connected and their separation might
be difficult.
• Screw two opposed screws to be used as grip, in order
to facilitate the extracting operation.
COMPONENTS INSPECTION
Magneto flywheel
• Control:
the integrity of the magnets.
That the magnets support cage does not
present any deformation or damages.
That the riveted joints of the flywheel do not
present any loosening.
F. 91
M
Freewheel
• Control that there isn’t any sign of anomalous wear on
the rollers.
F. 92
Starting ring gear
• Control that there isn’t any sign of excessive wear in the
toothing and hub.
B
• Check the diameter (A).
Ø (A) = 45,665
+ 0,008
+ 0,005
mm
• Check the diameter (B).
Ø (B) = 27
+ 0,020
+ 0,041
mm
A
F. 93
Anomalies occurring to the hub require the
replacement of the starting ring gear and the
freewheel; in case of excessive wear of the
bearing brass only (B), it is only necessary to
replace the starting ring gear. Control, in this
case, also the driving shaft.
37
05/04
G
500 cc
Intermediate gear and torque limiting device
• Verify the absence of anomalous wear to the toothing.
• Control the diameter (A) on both sides.
Ø (A) = 12
- 0
- 0,011
mm
A
• Control also the diameter of the seats within the engine
case and in the flywheel cover.
Ø 12
+ 0,034
- 0,016
F. 94
mm
Note - The torque limiting device is provided with four gears which operate as the driving disks of the clutch. The
driven disks have been implemented with four grooved Belleville washers, allowing to transmit torques which are
lower than 10 Kg*m. In case of wrong starting manoeuvres, the torque limiting device avoid counterstrokes, if any,
with consequent reversal of rotation of the driving shaft, which might cause serious damages to the engine.
The torque limiting device cannot be rebuilt; in case of anomalies, it is therefore necessary to replace
it.
38
05/04
500 cc
THERMAL UNIT AND
TIMING SYSTEM
H
INTAKE MANIFOLD
• Unscrew the screws (V3) and remove the whole intake
manifold unit.
V3
Cs - N*m
11 ÷ 13
V3
F. 95
TAPPETS COVER
• Unscrew and remove the screws (V6) and the relative
rubber seals.
• Remove the tappets cover and the relative gasket.
V6
F. 96
Before reassembling the tappet cover, clean it
accurately. Control the condition of the gasket
and, if necessary, replace it.
V6
Cs - N*m
7÷9
4
2
6
• Once reassembled the tappet cover, tighten the screws
(V6) (first the two screws shown in the picture with 1
and 2, then, in cross section sequence, the remaining
four screws: 3 - 4, 5 - 6).
V6
3
1
F. 97
39
05/04
5
H
500 cc
COMMANDE DE DISTRIBUTION
A
• Rotate the driving shaft so that to have the reference
(A) in the position shown in the picture (closing point of
the intake valves).
• Unscrew the central screw (V) and remove the stop bell
of the valve lifter mass, by using the special tool.
V
Cs - N*m
30 ÷ 35
F. 98
Special tooling:
Caliper wrench - code 020565Y
F. 99
• Remove the return spring, paying attention not to let it
fall inside the motor.
F. 100
40
05/04
V
H
500 cc
• Extract the valve lifter mass.
• Remove the stop washer, being careful not to make it
fall inside the engine.
F. 101
• Align the three points of reference: A - B - C.
F. 102
• Loosen the screw (V1) of the chain tightener.
• Unscrew the screws (V2) and remove the chain tightener
with the relative gasket.
Cs - N*m
5÷6
V1
V
V1
V2
Cs - N*m
11 ÷ 13
V2
F. 103
• Unscrew the screw (V) and remove the counterweight.
V
Cs - N*m
7 ÷ 8,5
V
F. 104
41
05/04
H
500 cc
• Remove the timing system chain gear.
F. 105
• Remove the “phonic” wheel (A).
F. 106
• Unscrew the fastening screw (V) and remove the “phaserev.” sensor and relative O-Ring ( NEW ).
• Remove the clamp from its hole on the head gasket.
For the inspection of the phase-rev. sensor,
please consult the Manual concerning the
Injection.
V
Cs - N*m
3÷4
V
F. 107
CAMSHAFT AND ROCKING LEVERS
• Unscrew the screws (V3) and remove the camshaft
retaining bracket.
V3
Cs - N*m
4÷6
V3
F. 108
42
05/04
H
500 cc
• Extract the camshaft.
F. 109
• Remove the pins and the rocking levers, operating
through the holes on the transmission side.
F. 110
CAMSHAFT INSPECTION
• Verify there isn’t any sign of anomalous wear or scorings
on the surface of the camshaft.
• By means of a micrometer, measure the various
diameters.
Ø A standard : 42
Ø A min.
mm
: 41,910 mm
Ø B standard : 20
Ø B min.
- 0,060
- 0,085
- 0,020
- 0,041
mm
: 19,940 mm
F. 111
• By means of a micrometer, verify the height of the cams.
Inlet
(standard) : 33,988
(min.)
: 33,740
mm
mm
Exhaust
(standard) : 33,417
(min.)
: 33,170
mm
mm
End play
(standard) : 0 ÷ 0,22 mm
(max.)
: 0,30
mm
F. 112
Note - Verify there isn’t any sign of anomalous wear in
the groove (C).
43
05/04
H
500 cc
FURTHER INSPECTIONS
• Verify that there isn’t any sign of wear on the automatic
valve lifter cam, on the counterweight, on the stop roller
and on the rubber beat of the retaining bell.
• Be sure that the valve lifter spring is not yielded.
• Finding out worn pieces, replace them.
F. 113
• Verify that the pins of the rocking levers do not present
any sign of excessive wear or scorings.
• Verify the internal diameter (A) of the rocking levers.
Ø standard pin
internal Ø A
: 13
- 0,010
- 0,018
mm
: 13
+ s0,026
+ 0,015
mm
• Verify that there isn’t any sign of wear on the contact
surface of the shoe (B) with the cam and on the pans
(C) of the registers.
• In case of excessive wear, replace the component.
F. 114
HEAD
• Remove the temperature sensor (S) of the coolant.
S
Note - For the inspections to carry out on the temperature
sensor, please consult the Manual concerning the
Injection.
S
Cs - N*m
10 ÷ 12
F. 115
NEW
• Cut the fastening clamp (A) or coupling.
• Remove the outlet coupling of the coolant system,
complete with its thermostat (T).
F. 116
44
05/04
A
H
500 cc
• Unscrew the fastening nut (A).
A
Cs - N*m
10 ÷ 12
F. 117
A
• Unscrew the fastening nut (B).
B
Cs - N*m
10 ÷ 12
B
F. 118
4
1
• Unscrew the two nuts (C - M6) and the nut (D - M6), complete
with its thermostat support.
C
Cs - N*m
10 ÷ 12
D
E
Cs - N*m
10 ÷ 12
• Loosen (repeatedly and in cross section sequence) the four
stud bolts (E) for the head-cylinder connection.
C
D
• During the reassembling operations, please see the following
instructions:
- Screw the four stud bolts in cross section sequence, as
shown in the picture, at the torque of 7 N*m.
Tighten of a 90° angle the four stud bolts, always in the
sequence shown in the picture.
- Tighten of further 90°, always in the sequence shown in
the picture.
E
Cs
7 N*m + 90° + 90°
45
05/04
2
F. 119
3
H
500 cc
• Extract the head unit with the utmost care.
Note - In this phase, provide for an adequate container
for the coolant container inside the thermal unit.
F. 120
• Remove the head gasket (G).
NEW
It is a steel-made gasket and its thickness is a
standard one.
G
F. 121
• Unscrew the fastening screw (V) of the chain tightening
shoe.
Cs - N*m
10 ÷ 14
V
V
F. 122
• Extract the chain tightening shoe, the chain guide shoe
and the chain itself.
Mark the chain, in order to guarantee the original
rotation way.
F. 123
46
05/04
H
500 cc
TIMING SYSTEM COMPONENTS INSPECTION
• Verify that the guide shoe and the tightening shoe are
not excessively worn.
• Control that there isn’t any sign of wear on the timing
system gear unit which controls the camshaft and the
driving shaft pinion.
• Finding out that the shoes are worn, replace them, or
should the chain or gear be worn, replace the whole
unit.
Note - Should the chain cause damages to the pinion, it
is necessary to replace the driving shaft, operating as
described within the chapter “Case and shaft”.
F. 124
VALVES
• By means of the special tool, complete with its adapter,
disassemble the cotters, the pans, the springs.
Tool for the removal of valves - code 020382Y
Adapter - code 020382Y012
F. 125
Lay down the valves so that to remember their
original position on the head (flywheel side and
transmission side).
• Remove the oil retainers by means of the special tool:
Extractor for oil retainers - code 020431Y
• Remove the spring supports, by injecting compressed
air into the housings, in order to facilitate the removal
operations.
CYLINDER
• Extract the cylinder (with care), the relative basket and
the dowel.
Support the piston during the removal of the
cylinder, in order to avoid damages.
NEW
NEW
F. 126
47
05/04
H
500 cc
PISTON
• Remove the two stop rings (A) of the piston pin, operating
through the specific slots.
• Extract the piston pin and remove the piston.
Occlude the piston housing (B) with paper or a
cloth, in order not to make accidentally fall the
stop rings of the piston pin or other objects
inside it.
B
F. 127
• Remove the piston pin from the piston.
F. 128
Take note of the original position of the piston
ring seals, so that not to make mistakes during
reassembling operations.
• Remove the O-rings and the scraper rings of the piston.
Do not damage the O-rings during the
disassembling operations.
F. 129
PISTON PIN CONTROL
• Check the outside diameter of the piston
pin.
Ø standard : 22
0
- 0,004
mm
F. 130
48
05/04
A
H
500 cc
CONNECTING ROD SMALL END INSPECTION
• Measure the diameter (A) of the connecting rod small
end.
Ø A standard : 22
+ 0,025
+ 0,015
mm
A
Finding out a higher diameter, replace
the connecting rod.
Note - Clearance (standard) between connecting
rod small end – piston pin : 0,015 ÷ 0,029 mm.
F. 131
PISTON INSPECTION
• Measure the diameter (B) of the pin seat, on
the piston.
Ø B standard : 22
+ 0,006
+ 0,001
mm
The measuring of the diameter has to be carried
out in accordance with the axis of the piston.
F. 132
The pin housings have two lubrication ways.
F. 133
Note - Accurately clean the housing of the sealing rings.
Verify, by means of a thickness gauge, the clearance (E)
between the O-rings and the slots of the piston.
E
1° Compression
Finding out higher clearance values than those
shown in the table reported here following,
replace the piston.
2° Compression
Scraper ring
F. 134
49
05/04
H
500 cc
Measures (mm)
Segmenti
1° Compression
O-rings
A = 0,9
- 0,005
- 0,030
C = 0,9
+ 0,003
+ 0,010
B = 1,5
- 0,005
- 0,030
D=2
+ 0,05
- 0,02
2° Compression
12
- 0,005
12,5
+ 0,03
Scraper ring
2,5
- 0,005
2,5
+ 0,03
F. 135
SEAL RINGS
Note - Insert the three piston ring seals in the area of the cylinder where the original diameter is maintained. The
insertion should be an orthogonal one (at this purpose use the piston).
Measure the “fissure” (opening) (E), of the rings, by means of the thickness gauge.
Finding out higher values than those shown in the table reported here following, replace the components (piston ring
seals).
E (mm)
Piston rings
Standard
Max.
Compression
0,15 ÷ 0,35
0,50
Scraper ring
0,25 ÷ 0,50
0,65
F. 136
Assembly
Note - The 2 seal segments are made with a cylinder
conical contact surface in order to reach a better setting.
The 1° compression piston ring seal has an “L” section.
Lubricate the parts with motor oil and use a “insertion”
special tool, in order to facilitate the assembling of the
piston ring seals.
M
F. 137
• Position the spring of the scraper ring on the piston.
• Install the scraper ring with the opening opposite to the
spring joint and the “top” writing facing the piston crown.
In any case, the machining chamfering has to be positioned
towards the piston crown.
• Install the 2° seal segment with the identification letter or
the “top” writing facing the piston crown. In any case, the
working step has to face the part opposite to the piston
crown.
• Install the 1° seal segment with the “top” writing or the
reference mark facing the piston crown.
• Stagger the segment openings at 120°, as shown in the
picture.
F. 138
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CYLINDER BASE GASKET SELECTION
• Install temporarily the cylinder on the piston, without the
base gasket.
• Install a test indicator on the special tool, using the short
coupling device, as shown in the picture.
Special tooling:
Support to check the piston position - code 020475Y
F. 139
• By means of a surface plate, reset the comparator with a
preloading of some millimetres.
• Fasten the comparator correctly.
• Verify the correct sliding of the feeler pin.
• Assemble the tool on the cylinder, without changing the
position of the comparator.
• Fasten the tool by means of the head fastening original nuts.
• Rotate the driving shaft until the P.M.S. (comparator’s rotation
reverse point).
• Measure, on the comparator, the deviation from the reset
value.
• By means of the here reported table, identify the thickness of
the cylinder-base gasket to use for the reassembling. The
correct identification of the cylinder-base gasket thickness
leads to the maintaining of the correct compression ratio.
• Remove the specific tool and the cylinder.
F. 140
Note - In case of deviations (protrusions or recesses) almost
in the proximity of the category change, repeat the measuring
from the opposite side. Repeat the device assembling by
inverting its position.
The measure “A” (without gasket) is a piston recess value; it
indicates how much the surface, formed by the crown of the
piston, goes down with respect to the surface, formed by the
advanced part of the cylinder. The more the piston descends
inside the cylinder, much lesser will be the “S” thickness of the
base gasket to apply (in order to restore the correct
compression ratio), and vice versa.
R = Recess
S = Projection
A
S
R/R
- 0,185 ÷ - 0,10
0,4 ± 0,05
R/S
- 0,10 ÷ + 0,10
0,6 ± 0,05
S/S
+ 0,10 ÷ + 0,185
0,8 ± 0,05
F. 141
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HEAD INSPECTION
• By means of a ground bar and thickness gauge, verify the
flatness of the head base.
max. tolerance allowed: 0,1 mm
• Then verify the bases of the manifolds: Intake and exhaust.
Finding out anomalies, replace the head.
F. 142
CYLINDER INSPECTION
• Measure the internal diameter of the cylinder (orthogonally
and at three different heights).
Ø standard : 92
+ 0,018
+ 0,010
mm
F. 143
Indication of the three heights at which is necessary to carry
out the measuring of the cylinder diameter (F. 144).
1
10
2
43
3
90
• Verify that the covering is not damaged or that there isn’t
any trace of “scaling”.
• Verify the flatness of the connection plane surface with
the head.
F. 144
max. tolerance allowed: 0,05 mm
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PISTON AND CYLINDER COUPLING
• Measure the external diameter (E) of the piston at the
height reported in the picture.
F. 145
• Measure the internal diameter (F) of the cylinder at the
height reported in the picture.
Note - Pistons and cylinders are classified into categories;
in function of the diameter, the coupling has to be carried
out in function of equal diameters:
(A - A / B - B / C - C / D - D).
Coupling category
Name
Cylinder
Piston
A
91,990 ÷ 91,997
91,947 ÷ 91,954
B
91,997 ÷ 92,004
91,954 ÷ 91,961
Assembling
clearance
F. 146
0,036 ÷ 0,050
C
92,004 ÷ 92,011
91,961 ÷ 91,968
D
92,011 ÷ 92,018
91,968 ÷ 91,975
VALVES CONTROL
• Control the conservation condition of the sealing
surface (A) of the valves; discontinued or bent
surfaces require the replacement of the valves.
Do not change the assembling position
of the valve (right - left).
F. 147
• Verify the diameter of the valve stems, at the
three points shown in the picture.
(mm)
Valve
Ø Standard
Intake work
4,987 ÷ 4,972
4,96
Exhaust work
4,975 ÷ 4,960
4,945
Ø min.
F. 148
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• By means of a concentricity support, verify the linearity
(deviation, if any) of the valve stems.
Max.: 0,01 mm
F. 149
• Rotate the valve and verify the perfect concentricity of
the head.
Limit allowed: 0,03 mm
F. 150
• Control the wearing condition of the part in contact with
the registers articulated terminal.
Valves standard length
Intake work
: 95,0 ± 0,3 mm
Exhaust work : 94,2 ± 0,3 mm
F. 151
VALVE RADIAL CLEARANCE CONTROL
• Measure the inner diameter of the valve guides and verify
the clearance with the stems previously measured.
RADIAL CLEARANCE (mm)
Valves
Standard
MAX.
Intake work
0,013 ÷ 0,04
0,08
Exhaust work
0,025 ÷ 0,052
0,09
F. 152
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INSPECTION OF THE WEAR OF THE VALVE SEATINGS
• Accurately clean the valve seats from any carbon residuals.
• Through the “Prussian blue”, control the impression on the
“V” valve seat.
Take down all measurements taking into account the
direction of the rocking lever thrust, at three different
levels.
“V” standard : 1 ÷ 1,3 mm
“V” max.
: 1,6 mm
F. 153
In case the impression width values on the valve
seat are higher than the expected limit values, rectify
the seats with a milling cutter at 45° and grind. In
case of excessive wearing or damages, replace the
whole head unit.
VALVE TIGHTNESS TEST
• Insert valves in the head.
• Test alternatively inlet and exhaust
valves.
• This test has to be performed filling
with gasoline the manifold and
checking that the head does not bleed
from the valves, holding them pressed
only with the fingers.
F. 154
F. 154/a
CAPS, COTTERS CONTROL
• Check that the superior support caps of the springs and the
cotters do not show unusual wears.
F. 155
SPRINGS INSPECTION
• Measure the free length (L) of the springs.
L - standard : 44,4 mm
L - min.
: 42,4 mm
F. 156
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INTAKE
MANIFOLD
I
INJECTOR
The injector has to be removed exclusively in
case we are sure of its malfunction. The
operative tests have to be carried out with the
injector assembled on the manifold.
V
• Unscrew the central screw (V).
• Extract the injector from the manifold.
F. 157
V
F. 158
THROTTLE VALVE
V3
The throttle valve is supplied complete with all
its components.
• Unscrew the screws (V3).
F. 159
The throttle valve is pre-set by the manufacturer.
Therefore avoid any intervention on the valve
register controlling the opening and closure of
the throttle valve itself, which has been
appropriately sealed for the idle adjustment.
Please consult the Manual concerning the
Injection.
• Accurately clean with a compressed air jet the gas valve
and the relative pipe.
F. 160
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500 cc
• Then clean the supplementary air pipe, controlled by
the “stepper-motor”.
F. 161
• Verify the good condition of the tightening lips on the
coupling level surfaces between manifold-throttle valve
and between manifold-head.
Air leaks, if any, might prejudice the
functionality of the injection system, in
particular when the motor is idling.
Note - After the replacement of the throttle valve, if
necessary, proceed with the T.P.S. reset and the
adjustment of the CO%.
F. 162
V
Cs - N*m
3÷4
V
NEW
P
L
243
V3
Cs - N*m
11 ÷ 13
Cs - N*m
11 ÷ 13
V3
NEW
NEW
F. 163
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CASING AND
DRIVING SHAFT
L
Before proceeding to the opening of the motor case, it is necessary to verify the end float of the shaft,
using the special tooling:
Crankcase separation plate - code 020262Y
Magnetic base with test indicator - code 020335Y
Standard play
: 0,10 ÷ 0,50 mm
Play max.
: 0,60 mm
OPENING OF THE ENGINE CRANKCASE
• Unscrew and remove the 14 case connecting screws.
Note - The fastening screws are of three different lengths.
Take note of the reassembling sequence.
Cs - N*m
V14 11 ÷ 13
F. 164
• Separate the cases, keep the driving shaft in position
on the half-case, flywheel side.
• Remove the connection gasket. NEW
F. 165
DRIVING SHAFT REMOVAL
Before removing the driving shaft, verify the
timing with the countershaft: rotate the driving
shaft until you obtain the alignment between
the two holes on the driving shaft with the hole
present on the control gear of the countershaft.
F. 166
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500 cc
• Remove the driving shaft with the shim adjustment
washer (A), flywheel side.
During the removal of the driving shaft, be
careful that the threaded parts do not enter into
contact with the bench bearing brasses.
F. 167
COUNTERSHAFT REMOVAL
• Fasten the special tool on the two threaded holes of the
case.
F. 168
• Special tool:
Countershaft stopping wrench - code 020479Y
F. 169
• On the opposite side of the case, unscrew and remove
the fastening nut and the relative washer.
Cs - N*m
Nut
25 ÷ 29
• Remove the special tool and extract the countershaft
complete with control gear.
M
F. 170
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500 cc
REASSEMBLING NOTES
P
L
243
P
P
P
F. 171
OIL PUMP REMOVAL
• Unscrew the screws (V2) and remove the case which
closes the oil pump compartment.
V2
Cs - N*m
8 ÷ 10
V2
F. 172
•Unscrew the two screws (V) (through the gear eyelets).
• Extract the oil pump, complete with its gear.
V
Cs - N*m
5÷6
V
F. 173
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500 cc
• Remove the gasket of the oil pump.
NEW
F. 174
BEARINGS REPLACEMENT
• Verify the correct smoothness of the bearings and the
absence of noise, frictions and anomalous wear.
Otherwise, proceed with their replacement.
• On the other side of the half case (flywheel side),
remove the bearing, by using the special tool and a fibre
mallet.
F. 175
Special tooling:
Adapter handle - code 020376Y
Adapter 37x40 code 020358Y
17 mm guide - code 020439Y
• Remove the bearing from the half case, transmission side.
Before assembling a new bearing, heat the half case (with an electrical heating gun), flywheel side.
Position the half case on a wooden level surface.
P
• Always grease the bearings seats, before their installation.
Note - The bearings with a plastic cage have to be assembled with the balls turned towards the internal side of the
case.
DRIVING SHAFT INSPECTIONS
• By means of a concentricity control support,
control the end float (A) of the connecting rod
(0,20 ÷ 0,40 mm).
• Control the radial clearance (B) of the
connecting rod (0,046 ÷ 0,076).
F. 176
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DRIVING SHAFT - CASE END FLOAT
Standard clearance (A): 0,1 ÷ 0,5 mm (cold).
B
DRIVING SHAFT - CONNECTING ROD
Standard size of the compartment (B): 22 -- 0,10
0,15
mm
A
F. 177
DRIVING SHAFT CONCENTRICITY INSPECTION
• Position the shaft on the concentricity control support;
measure the misalignment, if present, in the four
reference points shown in the picture.
Max. eccentricity value allowed (mm)
A = 0,15
B = 0,01
C = 0,01
D = 0,10
F. 178
• Verify the good condition of the driving shaft at all
reference points pointed out in the picture.
Note - In case of anomalies, replace the driving shaft.
The diameters of the bench “bearers” cannot
be grounded. The connecting rod cannot be
replaced singularly.
F. 179
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During the washing and cleaning operations
of the driving shaft, verify that are not inserted,
into the lubrication hole (A) of the driving
shaft, foreign matters or simple contraries.
In case of replacement of the driving shaft,
composed by two half shafts of different
category, it is also necessary to replace the
two half cases, pairing the shaft and the case
of the same category.
F. 180
• Verify the width (L) of the driving shaft, being careful
that the measure taken, has not been changed by the
radiuses.
“L” standard: 63,45 ÷ 63,60 mm
F. 181
ENGINE HALF CASE INSPECTION
• Clean, first thing, all the surfaces and all the lubrication
pipes.
• In the half case, transmission side, operate in
particular on the bench bearing brasses, on the cooling
jet (J) and on the lubrication pipe.
Note - The jet (J) is supplied by the bench bearing
brasses. The correct working of this component improves
the cooling of the piston crown. Its occlusion might
determine negative effects, which are really difficult to
be detected (increase of the piston temperature). Losses
or leaks may drastically lower the lubrication pressure
to the bench bearing brasses and to the connecting rod.
63
F. 182
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• For the half case, flywheel side, pay the utmost
attention to the lubrication pipes of the bench bearing
brasses, to the compartment and to the pipes of the
oil pump and to the by-pass pipe (B) located on the
flywheel cover.
Note - As already described in the “lubrication” chapter, it is extremely important that the by-pass housing
does not show any wears, which may compromise a
good seal of the piston adjusting the lubrication temperature. The duct for the head lubrication is equipped with a shutter jet: this causes a head lubrication of the “low pressure” type; this choice has been
made in order to contain the oil temperature in the
oil pan.
F. 183
The jet occlusion compromises the head lubrication and the timing mechanism. The lack of the jet
results in a reduction of the lubrication pressure both of the journal brasses and of the connection rod.
Check that the levels do not show any dents or deformations, paying particular attention to the cylinder-crankcase
levels and to the casing coupling.
A possible defect of the crankcase or levels coupling gasket may cause a leakage of the oil under pressure,
damaging the lubrication pressure of the journal brasses and of the connection rod.
Check that the containment surfaces of the driving shaft end play do not show any wear. To perform the dimensional check, refer to what explained for the checks of the end play and the dimensions on the driving shaft.
JOURNAL BRASSES INSPECTION
• In order to obtain a good lubrication of the journal brasses, it is necessary to have both an excellent lubrication
pressure (4 bar) and a good oil capacity; it is essential that the bearings are positioned correctly, so as to avoid
chokings of oil feeding holes.
• Journal brasses are made by 2 half bearings, one solid and one with holes and slots for the lubrications.
• The solid half bearing supports the thrusts due to the combustion, therefore it is positioned opposite the cylinder.
• In order to avoid chokings of the oil feeding holes, the coupling level of the two half bearings has to be perfectly
orthogonal to the cylinder axle.
• The section of the oil feeding holes is also influenced by the driving depth of the brasses, as to the containment level
of the driving shaft end play.
Note - To keep such position of the brasses on the crankcase, the driving has to be forced on steel rings cast-in in
both half casings.
• Check the brasses diameter in the 3 directions shown.
• Repeat the measurements for the other half of the
brass.
Avoid the measurements on the coupling level of
the 2 half bearings, avoid measurements on the
connection level surface of the two half bearings, in fact the ends can be adjusted so that to
allow a deformation during the driving.
• The standard diameter of the brasses after the driving
may vary according to a coupling selection.
• The seats of brasses in the crankcase are classified
in 2 categories as for the driving shaft: Cat. 1 e Cat. 2.
• Brasses are divided in 3 categories according to the
thickness; see the here reported table.
64
F. 184
TYPE
A
B
C
05/04
IDENTIFICATION
Red
Blue
Yellow
THICKNESS
1,982 ÷ 1,987
1,987 ÷ 1,992
1,992 ÷ 1,997
L
500 cc
COUNTERSHAFT INSPECTION
• Measure the diameters (A - B) of the countershaft.
Ø standard: 17
- 0,01
- 0,02
mm
• Verify that there isn’t any sign of excessive wear to the
water pump dragging device.
F. 185
OIL PUMP CONTROL
• Remove the screws (V2) and the oil pump cap.
Cs - N*m
V2 0,7 ÷ 0,9
V2
F. 186
• Remove the snap ring for the retaining of the internal rotor;
rotate it until you take the opening in correspondence with
the cut-off of the spindle.
• Remove the rotors, carrying out an adequate cleaning with
petrol and compressed air.
• Extract the spindle with its gears; verify its good conditions
and possible wearing on the spindle itself.
• Reassemble the rotors with the pump unit, so that the two
reference points are well in sight.
• Insert the spindle with gears, install the sealing ring and
rotate it, paying attention to keep the opening on the other
side of the spindle cut-off.
• Control if there is any anomalous clearance between
spindle and pump unit.
M
F. 187
• By means of a thickness gauge, control the distance (A)
existing between the rotors.
Limit clearance allowed: 0,012 mm
• Control the distance (B) existing between the external
rotor and the pump unit.
Limit clearance allowed: 0,25 mm
• Control the axial clearance of the rotors, using a rectified
bar as reference surface.
Limit clearance allowed: 0,1 mm
F. 188
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NOTES
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