onan toro power plus p216, 18, 20, 24 engines

ONAN TORO POWER PLUS P216, 18, 20, 24 ENGINES - HORIZONTAL
Table of Contents – Page 1 of 2
SAFETY PRECAUTIONS
GENERAL
PROTECT AGAINST MOVING PARTS
BATTERIES
FUEL SYSTEM
EXHAUST SYSTEM
EXHAUST GAS IS DEADLY!
COOLING SYSTEM
KEEP THE UNIT AND SURROUNDING AREA CLEAN
CAUTION
GENERAL INFORMATION
INTRODUCTION
ENGINE MODEL REFERENCE
SPECIFICATIONS
DIMENSIONS AND CLEARANCES
P216, P218, P220
P216,P218,P220
P224
P224
ASSEMBLY TORQUES
SPECIAL TOOLS
ENGINE TROUBLESHOOTING
OIL SYSTEM
CRANKCASE OIL
OIL FILTER CHANGE
CRANKCASE BREATHER
CRANKCASE BREATHER SERVICE
P216, P218, P220
P224
PRESSURE LUBRICATION
OIL PUMP
OIL BYPASS VALVE
FUEL SYSTEM
CARBURETOR
CARBURETOR SPEED SETTINGS
CARBURETOR OVERHAUL
REMOVAL
DISASSEMBLY
CLEANING AND REPAIR
REASSEMBLY AND INSTALLATION
PULSATING-DIAPHRAGM FUEL PUMP
FUEL PUMP TEST PROCEDURE
PURPOSE
CARBURETOR (BEGINNING SPEC G)
CARBURETOR HIGH-ALTITUDE JET (OPTIONAL)
AIR CLEANER
GOVERNOR SENSITIVITY
ONAN TORO POWER PLUS P216, 18, 20, 24 ENGINES - HORIZONTAL
Table of Contents – Page 2 of 2
IGNITION AND BATTERY CHARGING
IGNITION SYSTEM DESCRIPTION
IGNITION TIMING
CONTINUITY TEST
IGNITION COIL
SPARK PLUGS
BATTERY INSPECTION
BATTERY JUMP STARTING
FLYWHEEL ALTERNATOR
ALTERNATOR OUTPUT TEST
TYPICAL WIRING DIAGRAM
STARTING SYSYTEM
ELECTRIC STARTER
SERVICE
STARTER REMOVAL
STARTER DISASSEMBLY
STARTER ASSEMBLY
INSPECTION AND TESTING
STARTER MOUNTING
ENGINE DISASSEMBLY
DISASSEMBLY/ASSEMBLY
SUGGESTED DISASSEMBLY ORDER
SUGGESTED ASSEMBLY PROCEDURE
OPERATION
TESTING COMPRESSION
TAPPET ADJUSTMENT
VALVE SYSTEM
INSPECTION
TAPPETS
VALVE FACE AND SEAT GRINDING
FLYWHEEL
GEAR COVER
GOVERNOR CUP
TIMING GEARS
PISTONS AND CONNECTING RODS
CYLINDER BLOCK
CLEANING
INSPECTION
REBORING THE CYLINDER
HONING CYLINDERS (USING PRECISION HONES)
DEGLAZING CYLINDER BORES
CRANKSHAFT
BEARINGS
CRANKSHAFT ENDPLAY
CHECKING CONNECTING ROD BEARING CLEARANCE WITH PLASTIGAUGE
OIL SEALS
PISTON ASSEMBLY
INSTALLATION OF PISTON IN CYLINDER
CYLINDER HEADS
P216, P218, P220 INSTALLATION
224 INSTALLATION
Service Manual
1709
P216,18,20,24
TORO Power Plus
Engine
Tractors&RidingMowers
Safety Precautions
It is recommended that you read your engine manual and
become thoroughly acquainted with your equipment before
you start the engine.
Fuel System
DO NOT fill fuel tanks while engineis running.
DO NOT smoke or use an open flame in the vicinity
of the
engine or fuel tank. Internal combustion engine fuels are
highly flammable.
This symbol if used warns of immediatehazardswhich
will result in
severe personal injury or death.
Fuel lines must beof steel piping, adequately secured,
andfreefromleaks.Pipingattheengineshouldbe
approvedflexibleline., Do notusecopperpipingfor
flexible lines as copper will work harden and become
brittle enoughto break.
Thissymbolreferstoahazardor
unsafe practice which can result In
severe personal injury or death.
Be sure all fuel supplies have a positive shutoff valve.
This symbol refers to
a hazard or
unsafe practice which can result in
personal injury or product or property damage.
Exhaust System
Fuels,electricalequipmentbatteries,exhaustgasesand
movingpartspresentpotentialhazardsthat
can result in
serious, personal injury. Take care
in following these recommended procedures. All local. state and federal codes should
consulted
be and
complied
with.
This engine is not designed or Intended foruse in any type of aircraft.
Use of this engine
in aircraft can result
in engine failure
or death.
and causes serious personal injury
Exhaust productsof any internal combustion engine are
toxic and can cause injury,
or death if inhaled. All engine
applications,especiallythosewithinaconfinedarea,
should be equipped with an exhaust system
to discharge
gases to theoutside atmosphere.
Do not use exhaust gasesto heat a compartment
Make'surethatyourexhaustsystem
is free of leaks.
Ensure that exhaust manifolds are secure and arenot
warped bybolts unevenly torqued.
Exhaust G a sis Deadly!
Exhaust gases contain carbon monoxide, a poisonous gas
that can cause unconsciousness and death.
It is an odorless
and colorless gas formed during combustion
of hydrocarbon
fuels.Symptoms of carbon monoxide poisoning are:
General
Provide appropriate fire extinguishers and install them
in
convenient locations. Use an extinguisher rated
ABC by
NFPA.
Make sure that all fasteners
on the engine are secure and
accurately torqued. Keep guards in position over fans,
driving belts, etc.
If it is necessary
to make adjustments while the engine is
running, use extreme caution whento hot
closeexhausts,
moving parts. etc.
Protect Against Moving Parts
Do not wear loose clothing
in the vicinity of moving parts.
such as PTO shafts, flywheels, blowers, couplings, fans,
belts, etc.
Keep your hands away from moving parts.
Batteries
batteries
Before starting workon the engine. disconnect running.
to prevent inadvertent starting
of the engine.
DO NOT SMOKE whileservicingbatteries.Leadacid
batteries giveoff a highly explosive hydrogen gas which
can be ignited by flame, electrical arcing
or by smoking.
Verify battery polarity before connecting battery cables.
Connect negative cable last.
Dizziness
Headache
Weakness and Sleepiness
Vomiting
Muscular Twitching
Throbbing in Temples
If you experience any
of these symptoms. get out into fresh air
immediately, shut down the unit and do not use until it has
been inspected.
The best protection against carbon monoxide inhalation is
proper installation and regular, frequent inspectionsof the
complete exhaust system.
If you notice a change
in the sound
or appearance of exhaustsystem,shutthe
unit down
immediately and haveit inspected and repaired at once by a
competent mechanic.
Cooling System
Coolants under pressure have a higher boiling point than
water.,DONOTopenaradiatorpressurecapwhen
coolant temperature is above 212ºF (100ºC) or while
is
engine
Keep the Unit and Surrounding Area Clean
on or
Make sure that oily rags are not
leftnear the engine,
Remove all unnecessarygreaseand oil fromthe unit ~Accumulated grease and
oil can cause overheating and
subsequent engine damage and present a potential fire
hazard.
E-6
Table of Contents
TITLE
PAGE
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General Information
Specifications
Dimensions and Clearances
Assembly Torques and Special Tools
Engine Troubleshooting
Oil System
Fuel System
Ignitionand Battery Charging
Engine Wiring Diagram
Starting System.
................................................
......................................................
EnglneDisassembly... ...............................................
.1-1
.2-1
.3-1
.4-1
.5-1
.6-1
.7-1
.8-1
.8-7
.9-1
10-1
EXHAUST GASIS DEADLY!
Exhaust gasesfrom all fuels (Including diesel, gasoline, liquid propane, natural
gas) contain carbonmonoxide, an odorless
andcolorless gas. Carbon monoxide
is poisonous and can cause unconsciousnessdeath.
and Symptoms ofcarbon
monoxide poisoningcan include:
Dizziness
Nausea
Headache
Weakness and Sleepiness
Throbbing in Temples
Muscular Twitching
vomiting
Inability to Think Coherently
IF YOU OR ANYONE ELSE
EXPERIENCE,
ANY OF THESE SYMPTOMS, GET OUT
INTOTHEFRESHAIRlMMEDlATELY.
If symptoms persist, seek medical
attention. Shut down
the unit and do not operateuntil it has been inspected and
repaired.
Protection against carbon monoxide inhalation includes proper installation,
ventilationand regular, frequent visual and
audible inspections of the complete
exhaust system.
General Information
Use only Genuine
Tom Plower Plusreplacement parts to
ensure qualityand the bestpossible repair and overhaul
results. When ordering parts, always use the complete
model and spec number as well as the serial number
shown on the nameplate.
This manual deals with specific mechanical and electricalinformationneededbyenginemechanicsfor
or overhauling the
troubleshooting, servicing, repairing,
engine.
ENGINE MODEL REFERENCE
Usethe separate PARTS MANUAL for parts identification
and for establishing their proper location on assemblies.
The PARTS MANUAL contains detailed exploded viewsIdentifyyourmodelbyreferringtothemodeland
specification (spec letter) as shown on the unit nameof each assembly and
the individual piece numbers
part
and their proper names for ordering replacement parts. plate. Always use these numbers and the engine serial
to your engine.
number when making reference
The illustrations and procedures presented in each
How to interpretMODEL and SPEC NO.
section apply to the engines listed on the cover. The
flywheel-blower end of the engine is the front endso
right and left sides are determined by viewing the engine
from the front. The No. 1 cylinder is on the left, No. 2
cylinder is on the right.
If a major repair
or an overhaul
is necessary, a competent
-mechanic should either do the job or supervise and
check thework of the mechanic assigned to the job to
ensurethat all dimensions,clearancesandtorque
values are within the specified tolerances.
Use the table of contents for a quick referenceto the
separate engine system sections.
3
6
7
1. Factory codeforgeneralidentificationofbasic
engine series.
2. Number of cylinders.
3. BHPrating.
4. Fuel required(G= gasoline).
5. Engine duty cycle.
6. Factory code for designated optional equipment,
if
any.
7. Specification ( s p e c letter)whichadvanceswith
factory production modifications.
Thetroubleshootingguide
is provided as aquick
reference forlocating and correcting engine trouble.
The wiring diagram shows how the electrical components are interconnected.
Thedisassembly section contains major overhaul
proceduresforstepbystepremoval,disassembly,
inspection, repair, and assembly of the engine
components.
See the Operator's Manualfor fuel and oil recommendations and
the Periodic Maintenance Schedule.
INCORRECT SERVICE OR REPLACEMENT OF PARTS CAN RESULT IN
SEVERE PERSONAL INJURY AND/OR EQUIPMENT DAMAGE. SERVICE
PERSONNEL MUST BE QUALIFIED TO PERFORM ELECTRICALAND/OR
MECHANICAL SERVICE.
1-1
Specifications
This manual containsSI metric equivalents that follow immediately
in parentheses
after theU.S. customary units of measure.
2- 1
Dimensions and Clearances
P216. P218. P220
.
.
All clearances given at room temperature
70°Fof(21°C) All dimensionsin inches (approximate millimeter dimensions
in parentheses) unless otherwise specified
.
DESCRIPTION
CYLINDER BLOCK
Cylinder Bore Honed Diameter
Maximum Allowable
Taper
Out-of-Round
Main Bearing Inside Diameter (Without bearing)
Main Bearing Inside Diameter (Installed service bearing)
Camshaft Bearing Bore (Installed service bearing)
............................
(82.52)
3.2490
.................................................
.........................................
............. 2.1870
..... 2.001 5
........... 1.3757
CRANKSHAFT
Main Bearing Journal Diameter
Main Bearing Clearance
Connecting Rod Journal Diameter
Crankshaft End Play
1.9992
0.0024
1.6252
CONNECTING ROD
Large Bore Diameter(Rod bolts properly torqued)
Connecting Rod Side Clearance
Piston Pin BushingBore (Finished bore)
Bearing to Crankshaft Clearance
1.6280
0.0020
0.6879
............................
..................................
.........................
......................................
...........
...........................
....................
...........................
CAMSHAFT
Bearing Journal Diameter
Bearing Clearance
End Play
Lobe Height
P216. P218 Intake
P216. P218 Exhaust
P220 Intake
P220 Exhaust
.................................
.......................................
................................................
......................................
....................................
............................................
..........................................
PISTON
Clearance in Cylinder
Measure 90° to pin1.187 inch below top of piston
Piston Pin Bore
Ring Groove Width
Top Compression Ring
Middle Compression Ring
Bottom Oil Control Ring
.........
...........................................
.................................
...............................
.................................
3-1
0.0060
0.0020
1.3740
0.001 5
0.01 10
0.0033
(82.55)
3.2500
(34.94)
0.005
0.003
2.1 880
2.0040
1.3787
(0.1 3)
(0.08)
(55.58)
(50.90)
(35.02)
(50.78)
(0.061)
(41.28)
(0.1 52)
2.0000
0.0042
1.6260
0.01 20
(50.80)
(0.107)
(4130)
(0.305)
(41.35)
(0.051)
(1 7.47)
(0.051)
1.6285
(41
0.0160
0.6882
36)
(0.406)
(55.55)
(50.84)
0.0800
0.1 880
1.3745
(1 7.48)
(0.084)
(34.90)
(0.038)
0.0030
(0.279)
0.0480
1.1370
1.1 570
1.1670
1.1570
(28.88)
(29.39)
(29.64)
(29.39)
(0.084)
0.0053
0.6882
(0.135)
(1 7.48)
(2.032)
(2.032)
(4.775)
0.081 0
0.081 0
0.1 890
(2.057)
(2.057)
(4.800)
7.47)
0.6877
(1
0.0800
0.0033
(34.91)
(0.076)
(1.219)
P216. P218. P220
MINIMUM
Inches
(mm)
MAXIMUM
Inches
(mm)
PISTON PIN
Clearance in Piston
Clearance in Connecting Rod
Diameter
0.00004
0.0002
0.6875
(0.001)
(0.005)
(1 7.46)
0.00064
0.0007
0.6877
(0.016)
(0.01 8)
(1 7.47)
PISTON RINGS
Clearance
Top Groove
Ring End Gapin Cylinder
0.0030
0.0100
(0.076)
(0.254)
0.0080
0.0200
(0.203)
(0.508)
INTAKE VALVE
Stem Diameter
Clearance (Stemto Guide)
Valve Face Angle
0.2795
(7.099
(0.025)
0.0010 0.0025
02800
INTAKE VALVE SEAT
Seat Bore Diameterin Block
Seat Outside Diameter
Valve Seat Width
Valve seat Angle
1.4395
1.4700
0.0310
......................................
..............................
................................................
...........................................
.................................
...........................................
................................
........................................
...............................
.....................................
.........................................
.........................................
44º
1.4405
1.4710
0.0470
(36.56)
(37.34)
(0.787)
(36.59)
(37.36)
(1.194)
45º
EXHAUSTVALVE
...........................................
................................
Stem Diameter
Clearance (Stemto Guide)
Valve Face Angle
........................................
0.2780
0.0020
(7.061)
(0.051)
02785
0.0035
44º
EXHAUSTVALVE SEAT
Seat Bore Diameterin Block
Seat Outside Diameter
Valve SeatWidth
Valve Seat Angle
1.1890
1.1 920
0.0310
VALVE GUIDE
Intake Inside Diameter
Exhaust Inside Diameter
....................................
..................................
0.2810
0.2805
(7.1 37)
(7.1 25)
0.2820
0.2815
TAPPET
Body Diameter
Bore Diameter
Clearance in Bore
...........................................
............................................
........................................
0.7475
0.7500
0.0020
(18.99)
(19.05)
(0.051)
0.7480
0.7515
0.0040
1 600
(4.64
1.055
1.346
55 Ib
25 Ib
(26.80)
(34.19)
(25 kg)
(11 kg)
0.0010
(0.025)
0.0010
(0.025)
0.0080
(0.203)
27)
0.0050
(0.1
...............................
....................................
.........................................
.........................................
VALVE SPRINGS INTAKE AND EXHAUST
Valve Spring Free Length (Approx.)
Valve Spring Length
Valve Open
Valve Closed
Spring Load (Valve Open Length)
Spring Load (Valve Closed Length)
........................
............................................
..........................................
..........................
.........................
GEAR BACKLASH
Timing
Gear
Oil Pump
Gear
.............................................
...........................................
(30.20)
(30.28)
(0.787)
(30.23)
(30.30)
(1.194)
1.1900
1.1930
0.0470
45º
(1 9.00)
(1 9.09)
(0.1 02)
3-2
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
P224
DESCRIPTION
MINIMUM
Inches
(mm)
CYLINDER BLOCK
Cylinder Bore Honed Diameter
Maximum Allowable
Taper
Out-of-Round
Main Bearing Inside Diameter (Without bearing)
Main Bearing Inside Diameter (Installed)
Camshaft Bearing Bore (Bearing Installed)
2.1 870
2.0015
1.3757
(50.84
CRANKSHAFT
Main Bearing Journal Diameter
Main Bearing Clearance
Connecting Rod Journal Diameter
Crankshaft End Play
CONNECTING ROD
Large Bore Diameter (Without bearing installed and rod bolts
properly torqued)
Connecting Rod Side Clearance
Piston Pin BushingBore (Without bushing)
Piston Pin BushingBore (Finished bore)
Bearing to Crankshaft Clearance
............................
............... .................................
..........................................
.............
....................
..................
Inches
(90.49)
3.5635
(90.51)
(55.55)
(0.08)
(0.08)
(55.58)
(34.94)
0.003
0.003
2.1 880
2.0040
1.3787
1.9992
0.0024
1.6252
0.0060
(50.78)
(0.061)
(41.28)
(0.1 52)
2.0000
0.0042
1.6260
0.0120
(50.80)
1.7505
0.0020
0.81 15
0.7504
0.0020
(44.46)
1.7510
0.0160
0.81 25
0.7508
0.0033
(44.48)
(0.406)
(20.64)
(1 9.07)
(0.084)
(34.90)
(0.038)
(0.279)
1.3745
0.0030
0.0480
(34.91)
(0.076)
(1
1.1670
1.1 570
(29.64)
(29.39)
0.0070
0.7502
(0.1 78)
(1 9.06)
0.0090
0.7506
(0.229)
(1 9.07)
0.0800
0.0800
0.1880
(2.032)
(2.032)
(4.775)
0.0810
0.0810
0.1 890
(2.057)
(2.057)
(4.801)
PISTON PIN
Clearance in Piston
Clearance in Connecting Rod
Diameter
0.00004
0.0002
0.7500
(0.001)
(0.005)
(1 9.05)
0.00064
0.0008
0.7502
(0.01 6)
(0.020)
(1 9.06)
PISTON RINGS
Clearance
Top Groove
Ring End Gap in Cylinder
0.0020
0.0100
(0.051)
(0.254)
0.0080
0.0200
(0.203)
(0.508)
............................
..................................
.........................
......................................
........................................
...........................
..................
....................
...........................
CAMSHAFT
Bearing Journal Diameter
Bearing Clearance
End Play
Lobe Height
Intake
Exhaust
.................................
.......................................
................................................
..................................................
................................................
PISTON
Clearance in Cylinder
Measure 90°to pin 1.187 inch below top of piston
Piston Pin Bore
Ring GrooveWidth
Top Compression Ring
Middle Compression Ring
Bottom Oil Control Ring
.........
..........................................
.................................
...............................
.................................
.......................................
.............................
................................................
...........................................
.................................
3.5625
1.3740
0.0015
0.01 10
(0.051)
(20.61)
(1 9.06)
(0.051)
(50.90)
(35.02)
.
(0.1 07)
(41 30)
(0.305)
P224
DESCRIPTlON
INTAKE VALVE
Stem Diameter
Clearance (Stem to Guide)
Valve Face Angle
(8.700)
0.3425
0.0010
INTAKE VALVESEAT
Seat Cylinder Head Bore Diameter
Seat Outside Diameter
Valve Seat Width
Valve Seat Angle
(39.74)
1.5645
(39.85)
1.5690
0.0310
EXHAUST VALVE
Stem Diameter
Clearance (Stemto Guide)
Value Face Angle
0.3410
0.0025
EXHAUST VALVESEAT
Seat Cylinder Head Bore Diameter
Seat Outside Diameter
Valve Seat Width
Valve Seat Angle
1.2510
1.2550
0.0310
...........................................
................................
........................................
..........................
.....................................
.........................................
.........................................
...........................................
................................
.........................................
.........................
....................................
.........................................
.........................................
VALVE GUDE
Intake Inside Diameter
Exhaust Inside Diameter
TAPPET
0.3430
2) (8.71
(0.064)
1.5655
.57001
(39.76)
(39.88)
0.0025
(0.025)
44º
(1.194)
0.0470
(0.787)
45º
(8.687)
0.3420
(8.661)
(0.064)
0.0040 02) (0.1
44º
(31.78)
(31.88)
(0.787)
1.2520
1.2560
0.0470
(31.8 0 )
(31.90)
(1.194)
45º
....................................
...................................
0.3440
0.3440
(8.738)
(8.738)
0.3460
0.3460
(8.788)
(8.788)
...........................................
...........................................
........................................
'0.7475
0.7500
0.0020
(18.99)
(19.05)
(0.051)
0.7480
0.7515
0.0040
(19.00)
(19.09)
(0.102)
Body Diameter
Bore Diameter
Clearance in Bore
VALVE SPRINGSINTAKE AND EXHAUST
Valve Spring Free Length (Approx.)
Valve Spring Length
.Valve Open
Valve Closed
Spring Load (Valve Open
Length)
Spring Load (Valve
Closed Length)
........................
............................................
..........................................
..........................
..........................
GEAR BACKLASH
Timing Gear
Oil Pump Gear
.............................................
...........................................
3-4
(42.21) 1.662
1.125
1.375
71 Ib.
38 Ib.
0.0010
0.0010
(0.025)
(0.025)
.
(28.58)
(34.93)
(32 kg)
(17 kg)
0.0050
0.0080
(0.1 27)
(0.203)
Assembly Torques
Thetorquevaluesgiven in Table 1 havebeendeter-Tighten
all studs,nuts,andcapscrewsasrequiredto
minedforspecificapplications.Standardtorquevalueskeepthemfromworkingloose.Refer
to the PARTS
must not be used where those listed in Table 1 apply.
MANUAL for the location of washers and capscrews.
The engine assembly torques given here will assure
All
proper tightness without danger of stripping threads.
threads mustbe clean and lubricated with new engine
oil before torquing.
TABLE 1.
16,
TORQUE
P220 P218, P216,
IFICATION
DESCRIPTION
SPECIFICATION
DESCRIPTION
Nm
Gearcase
Cover
Rear
Bearing
Plate
Screws
Starter
Mounting
Bolts
Connecting R o d Bolts.
Flywheel
Capscrews
Oil Base
Oil Pump
Valve
Cover.
Head
Cylinder
Bolts
Other
(Cold)
Asbestos
Gasket
Graphoil
Gasket
Ft.-Lb.
Ft.-Lb.
................ 8-10
..... 25-27
34-37
......... 19-21
25-28
......... 12-14
16-19
........... 50-55
......................
18-23
24-31
.....................
7-9
10-12
................... 1-31-2
............ 22-24
16-1
8
............. 14-119-22
6
P224 P224
SPECIFICATION
DESCRIPTION
SPECIFICATION
DESCRIPTION
Nm
Gearcase
Cover
Rear
Bearing
Plate
Screws
Starter
Mounting
Bolts
Connecting Rod Bolts..
Flywheel
Capscrews
Oil Base
Oil Pump
Valve
Cover..
Other
(Cold)
Nuts
Head
Cylinder
(w/Compression Washers)
(w/o Compression Washers)
11-14
67-75
Intake
Manifold
Mounting
Screws..
Exhaust
Manifold
Mounting
Screws..
Other 1/4" Cylinder
Block
Stud Nuts..
and
Other 5/16" Cylinder
Block
Nuts
and
Stud
3/8" Block
Cylinder
Stud
and
Nuts
Nm
.......... 6-10
8-1
4
.......... 12-15
9-1
1
............. 10-12
7-9
............... 11-14
8-10
...............
18-23
24-31
TORQUE
Ft.-Lb.
Ft.-Lb.
............... 8-10
..... 25-27
34-37
......... 19-21
25-28
........ 27-29
37-39
........... 50-55
......................
18-23
24-31
.....................
7-9
10-12
................. 15-1
4-8
....
..
19 14
17
11-14
67-75
23
Special Tools
The following special tools are available
from
see TOOLCATALOG
Onan.Forfurtherinformation
900-0019.
Valve Seat Driver
Valve Guide Driver
Oil Seal Guide and Driver
Combination Bearing Remover (Main and Cam)
Combination Bearing Driver (Main and Cam)
Flywheel Puller
Intake
Manifold
Mounting
Screws..
Exhaust
Manifold
Mounting
Screws..
Other 1/4" Cylinder
Block
Stud
Nuts..
and
Other 5/16" Cylinder
Block
Stud
and
Nuts.
3/8” Block
Cylinder
StudNuts
and
.......... 20-23
27-31
.......... 12-1
9-1
1
.............. 10-12
7-9
.............. 8-10
11-14
............... 18-23
24-31
Nm
5
Engine Troubleshooting
ASOLINE ENGINE
FUEL SYSTEM
INTERNAL ENGINE
LUBRICATION SYSTEM
THROTTLE AND GOVERNOR
M-1686
Oil System
CRANKCASE OIL
Refer to Periodic Maintenance Schedule (located
in the
Operator's Manual) foroil change interval.If operating
in extremelydusty, high ambient, or low ambient
conditions, changeoil more often.
Hot crankcase oil can cause burns
if
His spilled or splashedskin.
on Keep
fingers and hands clear when removing the dl drain
plug and wear protective clothing.
Crankcasepressure can
blow out hot
oil and causeserious burns. Do NOT
check d l while the engine is Operating.
Oil level should be toFULL
the mark ofthe dipstick. Start
engine and run for a short time to check for
oil leaks
around the drain plug.
TORO POWER PLUS Engine
Do not overfill crankcase. Excessoil
causeshigheroperatingtemperaturesandmaycausefoaming.
Run engine until thoroughly warm before draining oil.
Stop the engine, place a pan under
drain
the outlet and
remove the oil drain plug. After the oil is completely
drained, clean and replace the drain
Fillplug.
crankcase
with correct
amount of oil. Refer to SPEClFlCATlONS for
crankcase capacity. Use oils meeting the API classification SF, SF/CC,or SF/CD.Refer to chart to determine
the proper viscosity grade oil
of to use. Straight weight
oilsarerecommendedforseveredutyuseandat
temperatures above 32ºF (0ºC) for minimum oil
consumption.
ALWAYS REPLACE
OR OIL
LEAKAGE MAY OCCUR
FULL
-
I
COOLING FINS
NOT OVERFILL
-
ADD REFER TO AMOUNT ON DIPSTICK
C-1000
FIGURE 1. CRANKCASE OIL FILL
FIGURE 2. OIL FILTER
OIL FILTER CHANGE
Refer to Periodic Maintenenace Schedule (located in
the Operator’s Manual) for oil filter change interval. If
operating in extremelydusty,highambient,
or low
ambient conditions, changeoil filter more often.
Spin off oil filter element and discard it. Thoroughly
clean filter mounting surfaceand
make sure new gasket
is inserted in the element. Applythin
a filmof clean oil to
the gasket. Spin element down by until
hand
gasket just
touches mounting pad and then turn down an additional
11/2-3/4 turn. Donot overtighten.
With oil in crankcase, start engine and check for leaks
around filter element.Retighten only as muchas
necessary to eliminate leaks; do not overtighten.
CRANKCASE BREATHER
The crankcase breather prevents pressurebuilding
from
up in the crankcase.It also preventsoil contamination
by removing moisture or gasoline vapors and other
harmful blow-by materials from the crankcase.
These
vapors are routed to the carburetor where they are
mixed with incoming air and burned
in the combustion
chamber. A sticky breather valve can causeoil leaks,
high oil consumption, rough idle, reduced engine power,
and a rapid formation
of sludge and varnish within the
engine.
BREATHER
Crankcase Breather Service
If the crankcase becomes pressurized as evidenced by
or excessive oil inthe air cleaner
oil leaks at the seals
housing, use thefollowing procedureto service.
Most parts cleaning solvents are
flammable and could cause serious
personal injury if used improperly.Follow the manufacturer’srecommendations when cleaning parts.
FIGURE 3A.
CRANKCASE BREATHER
- P216, P218, P220
P216, P218, P220
Remove the breather tube from the valve cover (Figure 3A). Remove capscrew, flatwashers, valve cover,
pack, spring, washer, reed valve, and breather baffle.
Discard gasketandclean all parts in part cleaning
solvent
HOSE
CLAMP
Over tightening the valve cover can
cause an air leak and allow dirt to
enter the engine. Be careful not to distort the valve
cover when tightening.
CLAMP
The reed valve must be flat with no sign of a crease.
Assemble using a new gasket. Do not overtighten valve
cover capscrew.
PACK
P224
Remove the breather hose from cap and valve assembly.
Remove cap and valve assembly and in
wash
a suitable
if balls do not move
solvent. Replace cap and valve
To allow free
freely. Puli pack out and wash in solvent.
operation of the valve, screens must be positioned as
shown in Figure 38.
6-2
-
FIGURE 3B. CRANKCASE BREATHER P224
PRESSURE LUBRICATION
Check oil pump thoroughly for worn
parts. Oil pump to
prime
it
before
reinstalling.
Except
for gaskets
pickand
All engines use an
oil pump to provide a constant flow of
up
cup,
component
parts
of
the
pump
are
not
available
oil to the engine parts. The
oil supply collectsin the oil
ifany parts,
individually. Install a new pump assembly
base whereit is picked upby theoil pump pick-up cup.
worn,. to control
are
A by-pass valve is used
oil pressure. Drain
oil
before removingoil base and always use
new
a gasket
Oil By-Pass Valve
when replacing theoil base.
The by-pass valve (located to the right and behind gear
Oil Pump
cover) controlsoil pressure by allowing excessoil to
flow directly back tothe crankcase. The valve limitsoil
The oil pump (Figure 4) is mounted behind the gear
20 (138 kPa) on the
cover and
is driven by the crankshaft
gear. Inlet pipe and pressure toa maximum of about psi
30
psi (207 kPa) on
P216,
P218,
and
P220,
and
about
screen assembly are attached directly to the pump
in pump cover registers with the P224 at normal operating temperature.
body. A discharge passage
a drilled passage in the crankcase. Parallel passages
The valveis non-adjustable and normally does not need
distribute oil to the front and rear main bearing and the
maintenance.Determine if valveis operating correctly
oil bypass valve.
by inspecting plunger action
as follows:
1. Remove thecap screw located behind gear cover
and under governor
arm.
2. Remove spring and plunger with a magnetic tool.
3. Determine proper valve operation by checking the
OIL PUMP PICK-UP CUP
springandplungeraccording
measurements:
Plunger Diameter
to thefollowing
.......... 0.3105 to 0.3125 in.
(7.89 to 7.94 mm)
Spring
Free Length
1.00 inch (25.4 mm)
L o a d ..... .... .2.6 ± 0.2 Ibs (11.6 ± 0.9 N)
whencompressedto 0.5 inch (12.7mm)
..............
.;.
OIL PUMP ASSEMBLY
CRANKCASE TURNED
ON LEFT SIDE
4. Check the valve seat and clean away any accumulation,of metal particles whichcould cause erratic
valve, action. Verify that the valve seat
is not
damaged.
in parts cleaning solvent
5. Clean plunger and spring
and install.
FIGURE 4. OIL PUMP ASSEMBLY
Circumferential grooves
in the main bearings supply
oil
to connecting rod bearings through drilled passages
A drilled passage connects the
from each main journal.
front main bearing oil supply to the front camshaft
bearing; rear cam bearing
is splash lubricated.
Normal oil pressure should be
8 psi (55 kPa) or higher at
1500rpmwhentheengine
is atnormaloperating
temperature. If pressure at 1500 rpm drops below this
value, inspect oil system for faulty components.
Fuel System
CARBURETOR
Note: See pages 7-4-1, 74-2 for Spec G Engines.
All carburetors have a fixed main
jet An optional fixed
main jet is available for altitude compensation above
5,000 feet.
Carburetor speed Settings
1. Start the engine andallowi t to warm up thoroughly
(at least10 minutes).
Some equipment manufacturers may require higher
throttle stop speed and governor low speed rpm
settings. Referto equipment manufacturer's Operator's Manual for the correct rpm settings. When
rpm settings are not specified by the equipment
inSteps 2
manu-factum, use the
rpm settings listed
and 3.
Thecarburetor idlemixture wassetformaximum
be
efficiency at the factory and should normally not
disturbed. If adjustments seem necessary,first be sure
the ignition system is working properly and governor
sensitivity is properly adjusted.
The carburetorhasa limited adjustment range
between
stops of±1/8turn. The screw should only
be adjusted
within these limits;in to lean the mixture, out to richen.
2. Move the engine
speed control to the slow position.
speed stop on the governor
so
Bend or turn the low
the throttle stop screw on the carburetor controls
engine speed. Adjust the throttle stop screw for
1000 rpm idle (Figures 1 and 2).
screw
forcingthemixtureadjustment
tight will damage the needle and
seat. Turn in only until light tension can be felt
3. Adjust the governor low speed stop for 1 1 0 0 rpm
If replacingidlemixturescrew,turn
in until lightly
seated, then turn screw back out 1-1 /4 turns for the
4.
P216,
P218,
and P220 carburetors, and1 -1 /2 turns for
the P224carburetor. Replace limiter cap with the plastic
stop approximately centered.
idle.
Move the engine
speed control to the fast position.
Bend the highspeed stop on the governor so the
engine runs at the equipment manufacturer's
recommended speed.
LOW SPEED
ADJUSTMENT SCREW
I
+
I
FIGURE 2. CARBURETORADJUSTMENTS
CARBURETOR OVERHAUL
Note: See pages 7-4-1, 7-4-2 for Spec G Engines.
Carburetionproblemsthatarenotcorrectedbymixture
adjustments are usually a result of gummed-up fuel
passages
internalparts.Themosteffective
solution is a carburetor overhaul.
FIGURE 3. CARBURETOR ASSEMBLY
orworn
In general, overhauling a carburetor consists of disassembly, athorough cleaning, and replacementwon
of
parts. Carburetor overhaul kits are available.
General instructions for overhauling a carburetor are
given below. Carefully note the position
all parts
of while
removingto assure correct placement when reassembling.Readthrough all the instructionsbefore beginning
for a better understanding of the procedures involved.
Carburetor components are shown
in Figure 3.
Ignition of fuel can cause serious
personal injury or death by tire or
explosion Do notanyflame,
cigarette, or other
igniternear the fuel system.
3. Remove the four intake manifold cap screws
lift and
complete manifold assembly from engine.
4. Remove carburetorfromintakemanifold.
Disassembly
1. Remove main jet and idle adjustment needle.
2. Remove attaching screws and separate upper and
lower carburetor sections.
Removal
1. Removecleaner
air assembly.
3. Carefully
note
position
2. Disconnect governor and throttle linkage, choke
and
control,
fuel carburetor.
line from
4.
valve.
needle
Remove
of float
assembly
parts,
then
pull out retaining pin and float assembly.
7-2
NEEDLE
\
BEND
TANG HERE
TO
BEND FLOAT ARM
HERE TO
FUEL
Cleaning and Repair
Reassembly and Installation
1. Soak all metal components not replaced
in carburetor cleaner. Do not soak non-metal floats or
other non-metal parts. Follow the cleaning manufacturer's recommendations.
2. Clean all carbon from the carburetor bore, especially
careful
where the throttle and choke plates Be
seat.
not to plug the idle or main fuel ports.
1. Install needle valve, main jet, and float assembly.
Make sure float pivot
pin is properly placed and float
moves freely without binding.
2. Turn carburetor on its side and measure float level
(Figure 4). Adjust float level only
if necessary.
Measure float drop (the distance from the top of
if
carburetorbodytotop
offloat).Adjustonly
necessary.
3. Dry outall passages with low pressure air
(35 PSI).
Avoid using wire or other objectsfor cleaning which
3. Position gasket on lower carburetor section and
may increase the size ofcritical passages.
install upper carburetor section.
4. Checktheconditionoftheadjustmentneedle;
if loaded with fuel
replace if damaged. Replace float
or damaged.
5. Check the choke and throttle shafts for excessive
play in their bore. This condition may necessitate
replacement of the carburetor.
4. Install idle adjustment screw, throttle stop screw,
and fixed main jet plug.
5. Mount carburetor on intake manifold and install
assembly on engine.
6. Connectgovernorandthrottlelinkage,choke
control, and fuel line. Mount air cleaner assembly.
6. Replace old components with new parts.
7. Adjust carburetor and governor according
directo
tions given in this section.
PULSATING-DIAPHRAGM FUEL PUMP
Pulsating-diaphragm fuel pumps, or pulse pumps, rely
on changesin crankcase vacuum to create
a pulsating
movementofthepumpdiaphragm.
As the engine's
pistons moveoutward, a vacuum is created.This
it
vacuum is transmitted to the pump diaphragm causing
to pull back and suck fuel
into the pump.
As the engine's
pistons move inward, crankcase vacuum
is reduced
and the diaphragm return spring pushes the pump
diaphragmforward, forcingfuelthroughthepump
outlet.
Spilled fuel ignite
can andcause
or death.
seriouspersonal injury
Thoroughly clean-up any spilled fuel.
7. Remove fuel outletline from fuel pump.
8. Connect a pressure gauge to fuel pump outlet using
a pieceof fuel hose with clamps.
9. Start engineandallowto
idle foratleastfive
seconds. While holding pressure gauge level with
pump outlet record pressure gauge reading.
10. Move throttle control
to high idle position and allow
engine to run for at least five seconds. While holdin
pressuregaugelevelwithpumpoutletrecord
pressure gauge reading.
Fuel Pump Test Procedure
11. Shut engine off and remove pressure gauge hose
fuel
outlet Connect fuel outlet to
line
Before testing make certain the fuel pump vacuum and from fuel pump
pump.
fuel line connections are tight and
free of leaks.
idlefive minutes to ensure
1. Operate engine at an for
that carburetor is full of fuel.
Replace the fuel pump
if test readings are not within the
values specified in TABLE 1.
TABLE 1
PULSE PUMP TEST SPECIFICATIONS
2. Shut engineoff and remove fuelinlet linefrom fuel
pump.
ENGINE
VACUUM
a
3. Connect a vacuum gauge to fuel pump inlet using SPEED
piece of fuel hose with clamps.
Low Idle
idle for at leastfive
seconds. Record vacuum gauge reading.
4. Start engineandallowto
Idle
High
--
5. Move throttle control to high idle position. Wait at
least five seconds and record vacuumgauge
reading.
6. Shut engine off and remove vacuum gauge hose
from fuel pump inlet. Connect fuel inlet line to fuel
pump-
7-4
PUMP INLET
(Minimum)
2.6 inches
mercury
of
2.6 inches
of mercury
PUMPOUTLET
PRESSURE
(Minimum)
1.7 psi
1.7 psi
A
Supplement to492-4006,492-4007
Date:1-95
P216/P218/P220/P224/P220V Service Manual
PURPOSE
This supplement transmits the revisions to the Service Manual necessary for covering
the Spec G engines listed above. Note that the nameplate on a Spec
G engine will
have the statement: “This engine meets1995-1998 California emissions regulations for
ULGE engines.”
To satisfy California emissions regulations, Spec G engines have internal engine
modifications and precision-manufactured carburetors with tamper-resistant fuel mixture
jets. It should therefore be noted that, other than installing the optional high-altitude jet
(Figure 4a), fuel mixture adjustments should not be attempted. Nor should. the
carburetor be overhauled. Instead, a malfunctioning carburetor (seeEngine
Troubleshooting)should be replaced.
California users should note that
unauthorized modifications or replacement of
fuel, exhaust, air intake, or speed control system components that affect engine
emissions are prohibited by California regulationsand that the optional highaltitude mainjet is not intended for use in California. Modification, removal or
replacement of the generator set labelis also prohibited.
7-4-1
CARBURETOR (BEGINNING SPEC G)
Carburetor Replacement
Other than replacing the carburetor main fuel jet
(fixed-type) with the optional high-altitude jet (Figure &), fuel mixture adjustments should not be attempted. Nor should the carburetor be overhauled.
Instead, a malfunctioning carburetor shouldbe replaced. Before replacinga carburetor,however,
make certain 1) that all other necessary engine and
generator adjustments and repairs have beenperformed and 2) that the carburetor is actually mal(see
functioning
Engine Troubleshooting).
STOP SCREW
LEVER
To remove the carburetor, remove the air cleaner,
disconnect the fuelline and choke and throttle linkages and unbolt the carburetor from themanintake
ifold. When mounting the carburetor alwaysuse a
new gasket. Readjust the choke and throttle cables
and engine speed as instructed in the engine or
equipment Operator's Manual.
Carburetor High-AltitudeJet (Optional)
If the engineis operated at an altitude above 5,000
feet (1,524 metres), it is recommended that the carburetor main fuel jetbe replaced withthe optional
high-altitude jet (which has a slightly smaller orifice).
IDLE
OVER
PUMP
PLUG
MIXTURE NEEDLE
To avoid slippingand gouging the
main fuel jet, use a screwdrlver with 5/16
a inch
(8 mm) wide blade.
CHOKE
REMOVE
CAP FOR
ACCESS TO MAINJET
MAIN FUEL JET
(shown enlarged)
FIGURE 4a. CARBURETOR
AIR CLEANER
ELEMENT
AIR
PLATE
.
FIGURE 5. AIR CLEANER ASSEMBLY
AIR CLEANER
If air cleanerbecomes too dirty,
engine will not receive sufficientair
to run properly. Symptoms: Loss of power, flooding,
hard starting and overheating.
Engine is equipped with a paper element.
If the engineis
it must be removed,
equipped with an element wrapper,
cleaned, and oiled every 25 hours of operation; more
often under extremely dusty conditions.
1. To cleanelementwrapper,wash
GOVERNOR SENSITIVITY
These engines are adapted for use where a wide ran
of speed settingsis desired. Engine speedis controlled
at any given point between minimum and maximum by
simply shifting the throttle lever on the control panel
until the desired speedis reached.
A reliable instrument for checking engine speed
requiredforaccurategovernoradjustment.Engine
speed can be checked with a tachometer.
is
in waterand
Check the governor arm, linkage, throttle shaft, and
lever for binding condition or excessive slack and wea
detergent(Figure 5). Removeexcesswaterby
asponge, and allow to dry thoroughly. at connecting points. A binding condition at any point
squeezing like
will
will cause the governor to act slowly and regulation
Distributeonetablespoon ofSAE 30 engine oil
evenly around the precleaner. Knead into precleaner be poor. Excessive looseness may cause a hunting
condition and regulation could be erratic. Work
armthe
and wring out excess oil.
back and forth several times by hand while the
is engin
2. Depending on conditions in which the engine is
idling to check for above conditions.
operating, the inner paperelementshouldbe
replaced wheneverit becomes excessively dirty or
oily.
Never run engine withair cleaner
engine
enter
Dirt will
removed.
and wear out rings causing excessive blow-by.
THROTTLE STOP
SCREW
GOVERNOR CONTROL
LINKAGE
GOVERNOR
SPRING
SIDE PULLGOVERNOR
FRONT PULLGOVERNOR
FIGURE 6. VARIABLE SPEED GOVERNOR ADJUSTMENTS
On sidepull governors the governor spring
is set by the
factory in the third hole of the governor arm (third hole
from pivot). On front
pull governors the governor spring
is set by the factory
in the second hole
of the governor
1. Disconnect linkage(A) from one of holes(C).
armadapter(secondholefrompivot).
To increase
sensitivity, move spring loop into a hole closer to the
2. Push linkage(A) and governor arm(B) as far back
pivot. To decrease sensitivity, move spring loop into a
toward carburetor as they
will go.
hole farther away from the pivot. After sensitivity has
3. Holding linkage and governor arm toward direction been set, recheck the low speed rpm setting. Adjust if
of carburetor, insert endof linkage into whichever
necessary.
hole (C) in governor arm lines up the closest. If
between two holes, insertin next holeout.
If the governor is hunting or not operating properly,
adjust asfollows (Figure 6):
Ignition and Battery Charging
IGNITION SYSTEM DESCRIPTION
Failure to ground spark tester
away from spark plug hole may
result in ignition
of cyiinder gasesandmay cause
severe personal injury.
Thisengine is equippedwithanelectronicbattery
ignition system. Both spark plugs fire simultaneously,
thustheneedforadistributor
is eliminated.The
electronic ignition module
is located on the enginegear
2. Pull spark plug wires off spark plugs and remove
cover behind the flywheel. The module receives a timingspark plugs. Connect an approved spark tester to
signal from magnets within the trigger
ring which rotates
each of the spark
plug wires and ground them away
with the engine crankshaft (Figure
1). If the electronic
from sparkplug hole. Turn key on and crank engine
ignition is suspectedofmalfunctioning,proceedas
over for 5 seconds while watching for spark. If a
follows:
spark occurs regularly, the problem is not in the
3.
ignition system. If no spark occurs, go to step
Never put jumper lead
to the coil
negative
terminal.
Thiswill
cause
failure of the electronic ignition module.
3. Connect a jumper lead directly from the positive
(+) coil terminal
batteryterminaltothepositive
(smaller diameter of the two threaded posts). Crank
If spark
engineoverwhilewatchingforspark.
occurs, the problem
is in the lowoil pressure cut out
switch (if equipped) or related wiring, the lubricatin
system (low oil pressure), or in the other circuitry
bringing voltage to the coil.
If no spark occurs, go to
step 4.
4. Refer to IGNITION COIL sectiontotest coil for
proper resistance. If coil checks out good, go to
step 5.
IGNITION
MODULE
ES-1670
FIGURE 1. IGNITION MODULE AND TRIGGERRING
1. Check all electrical connections to be sure they are
clean and tight. If all connections are good and
wiring is intact, go to step2.
The electronicignitionwill
deliver full voltage to the spark
plugs even when rotated by hand.Care should be
taken to avoid anelectrical shock.
5. Connect positive side of voltmeter to negative (-)
coil terminal (larger diameter of the two threaded
of voltmetertoengine
posts)andnegativeside
ground. Turn key on and rotate flywheel slowly by
handwhileobservingvoltmeter.Voltageshould
1-1.5 for each
switch between battery voltage and,
revolution.Ifvoltagedoesnotswitchproperly,
replace ignition module.
Neverput B+ leadtothecoil
negative terminal.Thiswill cause
failure of the electronic ignition module.
6. Install spark plugs and wires.If ignition module is
being replaced, be sure to connect red lead from
new ignition module to positive(+) terminal of coil,
black lead from module to negative (-) terminal of
coil.
Failuretoremovesparkplugs
before turning engine over may
resultinenginestarting,whichmaycausesevere
personal injury.
8- 1
IGNITION TIMING
The ignition timing is preset at the factory and is not
adjustable. For troubleshooting purposes,it is possible
to make an approximate check of the ignition timing
usingreferencemarksontheblowerhousingand
flywheel (Figure 2). This check can be performed by a
continuity test.
4. Rotate the flywheel slowly by hand
in the clockwise
direction until the voltmeter reading switches from
approximately 1 volt to battery voltage. At this point,
one of the chaff screen screws should
lie between
the two reference marks on the blower housing. To
be rotated another
recheck timing, the flywheel must
completerevolution in theclockwisedirection.
Movingtheflywheelbackandforthacrossthe
reference timing mark
will not activate the electronic
ignition control.
5. Install spark plugs and wires.
,
IGNITION COIL
To testprimaryandsecondarywindingswithinthe
ignition coil first make sure the ignition power
is off and
coil is at room temperature of 70°F (21 "C).
1. Use a Simpson 260VOM or equivalent.
BLOWER
TIMING
2. Place a black lead on negative
(-) coil terminal and
red lead to positive (+) coil terminal.Primary
resistance should read between 2.90-3.60 ohms.
3. Changeresistancesettingonohmmeter.Place
ohmmeter leads inside of spark plug cable holes
(Figure 3). Secondaryresistanceshouldread
between 14,500-19,800 ohms.
4. If eitheroftheaboveresistancesarenotwithin
M-1675
specification,
replace
coil.
FIGURE 2. IGNITIONTIMING MARKS
Continuity Test
1. Pull spark plug wires off spark plugs and remove
spark plugs.
Failure to removesparkplugs
before turning engine over may
result in engine starting, which may cause severe
personal injury.
2. Turn ignition on.
3. Connect a voltmeter between the negative(-) coil
terminal (larger diameter of the two threaded posts)
and a good engine ground.
Theelectronicignitionwill
ddeliver full voltage to the spark
plugs even when rotatedby hand. Care should be
taken to avoid an electrical shock.
FIGURE 3. COILTEST
SPARK PLUGS
Keep the battery terminals clean and tight. Push the
cable terminal down flush with
or slightly below the top
6). After making connections,
of the battery post (Figure
Check or replace spark plugs as recommended
in the
coat the terminals with light
a application of petroleum
Periodic Maintenance Schedule(located in Operator's
jelly orgrease to retard corrosion.
Manual). Replace spark plugs that show signs of fouling
or electrode erosion.
Poor contact at the battery cable connections
is often a
source of trouble. Make sure battery cables
in good
are
condition and that contacting surfaces are clean and
tightly connected. Do not reverse battery leads. Use
recommended battery tools when disconnecting leads
to avoid mechanical battery
damage.
FIGURE 4. SPARK
PLUG
GAP
BATTERY POST
BATTERY INSPECTION
Ignition of explosivebattery gases
can cause severe personal injury.
not smoke while servicing batteries.
FIGURE 6. BATTERYCABLECONNECTION
Checkbattery cells with ahydrometer (Figure 5).
Specific gravity reading should be between
1.260 and
1.290 at 77°F (25°C).
If one or more
cells are low on water, add distilled water
and recharge. Keep the battery case clean and dry. An
accumulation of moisture or dirt will accelerate discharge and battery failure.
SPECIFIC
GRAVITY READING
SHOULD BE
1.260 at
(25°C)
BATTERYJUMPSTARTING
Occasionally, it may be necessary to jump start (charge)
a weak battery using a charged booster battery. If jump
starting is necessary, the following procedure
is recommended to prevent starter damage, battery damage, an
personal injuries.
1. Disconnect engine load.
2. Use a battery of the same voltage (1 2V) as
is used
with your engine.
3. Attach one end of the positive booster cable (red)
thepositive (+) terminal of theboosterbattery.
Attach the other end of the positive cable to the
positive (+) terminal of your engine battery.
FIGURE 5. SPECIFICGRAVITYTEST
Do not allow the posltive and
negativecable ends to touch
each other because itwill short the battery causing
hazardous arcing, which can cause severe personal injury.
4. Attach one end of the negative booster cable (black)
to negative (-) terminal of booster battery. Attach
otherendofnegativecable
ground
on
to asolidchassis
Never jump start a frozen battery. To do so can cause the
battery to explode. Never expose the battery to an
open flame or an electrlcalspark because
a battery
creates highly explosive
hydrogen
gas.
6. Turn ignition switch to ON to start engine.
ALTERNATOR
FLYWHEEL
5.
Weak ignition spark or a discharged battery indicates
trouble in the charging system.Beforetestingthe
engine's chargingsystem, always check the battery for
serviceability.
STATOR
MOUNTED BEHIND
BLOWER WHEEL
TOSTARTERORBATTERY
CAUTION:
REGULATOR MUST BE GROUNDED
THROUGH MOUNTING BOLTS
VOLTAGE
REGULATOR
CONNECTIONS
ES-1333-1
FIGURE 7. FLYWHEELALTERNATOR SYSTEM
EO-1532
Keep these points
in mind when testing or servicing the
flywheel alternator:
ALTERNATOR OUTPUT TEST
Use a volt-ohmmeter, such as the Simpson
270, when
testing the charging system.
1. Be sure engine is being run long enough and fast
enough to recharge battery after each start. Charging
system tests requirefulla charged battery. Alternator 1. Check battery voltage with unit not running. If not
output is reduced in direct proportion to engine
rpm.
1) charge battery before
within specifications (Table
Also, power required for accessories reduces power proceeding to step 2.
available to recharge battery.
2. With the engine running, check the battery terminal
2. The regulator-rectifier has built
in protection against
voltage(regulatoroutput)usingaDCvoltmeter.
open circuits orshort circuits onthealternator
Voltage output should be within the values speci
will cause the
output (B+) terminal. Either condition
in Table 1.Ifvoltage
is greaterthanspecified,
if it is not
regulator-rectifier to shut off and appear
as
replace regulator-rectifier assembly. If voltage is
functioning. Priortochecking the regulator-rectifier,
3.
less than specified, proceed to step
check all wiring between the regulator-rectifierB+
terminalandthebatterypositive
(+) terminalto
assure it is free of open circuits, resistances or short 3. Examine all wires for loose, corroded, broken concircuits. Also, if the batteryis extremely discharged
nections, short circuits, etc. Check fuses. Repair as
it mayhaveinsufficientpowerto“turnon”the
needed to assure complete
circuits from regulatorregulator-rectifier.
rectifier B+ terminal to battery positive(+) terminal
and from battery negative(-) terminal to regulatorrectifier case. If battery voltage remains low with
3. Be sure regulator-rectifier plug (connector) is in4.
engine running, proceed to step
serted properly. Plug must bottom
in receptacle; this
eliminates any resistance due to a poor connection.
Keep clean and tight.
4. Disconnect plug from regulator-rectifier and test
If AC
the AC voltage at the
plug with engine running.
voltage reads more or less than specified
in Table 1,
4. Make sure alternator stator leads are not shorted
proceed to step5. If AC voltage is as specified but
together.
DC voltage is low, replace regulator-rectifier.
5. Besureregulator-rectifierhasagoodground
connection. Mating surface for mounting must be
clean and fasteners tightened properly.
6. Never reverse the battery leads.
When the engineis running between1800 to 2600 rpm,
observe the panel ammeter (if not already equipped,
connect a test ammeter). If no charging is evident,
proceed with theAlternator Output Test.
5. Use theRx1scale on the ohmmeter for detecting an
openorground in thestator(unitnotrunning).
Disconnect plug from the regulator-rectifier. Connectoneohmmetertestleadtoastatorwire,
connecttheothertestleadtoground.Reading
should show an open (no continuity).If it doesn’ t,
stator must be replaced. If reading shows no continuity connect one ohmmeter lead to each wire
coming from the stator. Refer
to Table 1 for resistance specifications.If resistance is not as specified,
replace stator. If stator resistance readings are as
specified and windings are not shorted or open,
AC voltage maybe due toloss of magnetism. If so,
blower wheel assembly must
be replaced.
TABLE 1. TESTING 20 AND 35 AMPERE SYSTEMS
STATOR
RESISTANCE
PROCEDURE
Refer to Alternator
Output Test
0.06 to 0.10 Ohms
0.10 to 0.19 Ohms
13.6 to 14.7
VDC
Approximately
24
VAC
0.06 to 0.10 Ohms
TYPICAL WIRING DIAGRAM
STARTER
*AMMETER
(OPTIONAL)
ACCESSORIES
START
OIL PRESSURE
SWITCH N C
LOW
PRESSURE WARNING
LIGHT OR HORN
WITH OIL PRESSURE SWITCH FOR LIGHT
& y e -
*FUSE
STARTER
*AMMETER
These typical wiring diagrams show the basic wiring necessary
for operation of the engine. Your engine may
differ in circuitry and features depending on how the equipment manufacturer chose to configure the final
product.
Starting System
ELECTRIC
STARTER
1. Remove both
battery
cables
from
battery.
Discon-
nect ground cable first.
Normally the starter
will require little or no service other
if through
thanpossiblebrushreplacementHowever,
accident
or
misuse,
the
starter
requires
service
or
from
starter.
will providetheinformation
overhaul,thefollowing
necessary to perform this service.
2. Disconnectbatterycableand electrical leadwires
3. Remove starter motor.
Starter Disassembly
Service
Whenstartingengine,notestartermotoraction.The
1. Remove “M” terminal nut andwire lead from
1).
piniongearshouldmesh quickly with flywheel ring gearsolenoid(Figure
andspinengine.Onceenginestartsandsolenoid
Ifstarter
2. Removethe two solenoidmountingscrewsand
opens,thestartershoulddisengageandstop.
cranks
engine
slow,
or
not
at
all,
check
start
circuit
remove
solenoid.
components. Failure to crankis normally causedby low
3. Scribeamarkacrossframeandrearbrackettoaid
batterycharge,defectivebatterycables,corrodedor
in assembly.Removethe two throughbolts.
poorconnections,orlowtemperatures. If afterchecking
these variables, starter continues to crank slowly, starter
4. Remove
bracket
rear
frame
and
assembly.
removed
must
berepaired.
and
5. Carefullyremovearmatureand
lever fromfront
bracket. Note direction of lever and retainer.
Starter Removal
Accidentalstarting of the enginecan
personal
severe
cause
injury or
death. Disconnectthe battery cables when repairs
are
made to the
engine,
controls,
or housings.
6. Removethe two brushmountingscrews,and
rear themove
bracket
7. Remove
brush
holder
assembly
from
the
frame
by
pulling the brushesout
SOLENOID
FRONT
BRACKET
RETAINER
THROUGH
ARMATURE
SCREW
FIGURE 1. STARTERMOTOR
re-
ring
8. Push stopper toward pinion and remove snap
(Figure 2).
9. Removestopper and overrunning clutch from
armature shaft.
CLUTCH
\
STOPPER
a=-
ST
SNAP RING
FIGURE 2.
REMOVINGOVERRUNlNG CLUTCH
10 Inspect starter for damaged
or worn parts.
11. Repair or replace all damaged or worn parts as
needed.
Starter Assembly
I
4. Lubrication:When starter motor is assembled apply
grease to each of the
following points (Recommended grade: Multitemp PSNo. 2):
Armature shaft spline
Both bushings (Both ends
of armature)
Stopper on armature shaft
Pinion gear
Sliding portionof lever
5. Fit overrunning clutch into lever, and install with
armature in the frontbracket
1. Installsealinnosehousing.Installoverrunning
clutch on the armature
shaft.
6. Installleverretainerandspacer.Positionframe
assembly over armature on the front bracket.
2. Slide stopper on the armature shaft. Position snap
ring in groove in armature shaft.
7. Install brush holder assembly. Position brushes in
brush holder. Make certain positive lead wires are
not grounded.
3. Pull stopperall the way over snapring (Figure 3). It
8. Installwashers,asrequired,ontherearendof
armature shaft to obtain an armature shaft thrust
gap of 0.002 to 0.02 inch (0.05 to 0.5 mm).New
washers are requiredif rear bracket is replaced.
may be necessary to tap snap
ring into groove with a
punch while maintaining tension
on stopper.
Table 1. Starter Assembly Torques
Brush Retaining Screws
Through Bolts
9. Install rear bracket. Secure brush holder to rear
bracket withtwo machine screws.
10. Install and tighten the two through capscrews.
11. Install solenoid plunger
in lever. Secure solenoid to
front bracket with two machine screws.
COMMUTATOR BARS
12. Install wire lead to the terminal
“M” on solenoid.
13. Afterassembly,adjust
pinionclearance.Pinion
be 0.02
to 0.08 inch (0.5 to 2.0 mm);
clearance should
if not, check as follows (Figure
4):
A. Connect starter to a battery. Close switch. This
will shift pinion into cranking position.
B. Push pinion back by hand and measure pinion
clearance. If clearance does not fall within the
specified limits, adjust by adding or removing
shims located between solenoid and front
bracket Adding shims decreases clearance;
removing shims increases clearance. Shims are
included with replacement solenoid.
ES-1001
FIGURE 5. TESTINGARMATUREFORGROUNDS
TestingArmature for an OpenCircuit: Using an
ohmmeter, check for continuity between the commutator
segments. If there is no continuity (high resistance), the
be replaced.
segments are open and armature must
PINION
Testing Armaturetor a Short Circuit: Use a growler for
6). Place armature
locating shorts
in the armature (Figure
in growler and hold a thin steel blade (e.g. hacksaw
blade) parallel to the
core and just aboveit while slowly
rotating armature in growler. A shorted armature will
cause the blade to vibrate and be attracted toIf the core.
armature is shorted, replace with a new one.
BATTERY
FIGURE 4.
PINIONCLEARANCEADJUSTMENT
Inspection and Testing
Inspect the starter components for mechanical defects
before testing for grounds or shorts.
TestingAmature tor Grounds: Touch armature shaft
or
core and the end of each commutatorwith
bar a pair
of
ohmmeter leads (Figure 5). A low ohmmeter reading
indicatesagroundedarmature.Replacegrounded
armature.
ES-1002
FIGURE 6. TESTINGARMATURE FOR SHORT CIRCUITS
Commutator Inspection:If commutator is dirty or dis00 to 000 commutator
colored,cleanwithnumber
paper. Blow grit out of armature after cleaning.
Overrunning Clutch:Inspect pinion and spline teeth for
wear or damage.
If commutator is scored, rough, or worn, turn
it down in a
lathe.
If pinion gear is worn or damaged, inspect flywheel ring
It should turn free when turned
gear also. Rotate pinion.
in one direction, andlock when turned in the opposite
direction.
Field Coil: Use an ohmmeter to check for continuity
coil is
between brushes.If there is no continuity, the field
open and must be replaced. With fieldcoil mounted in
the frame, check for continuity between coil
the and
field
frame. Replace frame assemblyif there is continuity.
Do not clean overrunning clutch in
solvent or liquid cleaning solution.
Washing the clutch will causethe grease to leak out.
off
Brushes: Clean around brushes and holders, wiping
all brush dust and dirt.
If brushes are worn shorter than
.4528 inch (11.5 mm) replace them (Figure7).
Solenoid: Push solenoid plungerin and release it. The
plunger should return to
its original position.While
holdingplunger all thewayin,checkforcontinuity
between terminals“M”and “B’. If there is no continuity,
replace the solenoid (Figure
8). After replacing solenoid
check pinion clearance.
WEAR
LIMIT
ES-1345
FIGURE 7. BRUSH WEAR
FIGURE
LIMIT
Check for shorts between positive side of brush holder
and brush holder base. If there is continuity, replace
holder assembly. Check for free movement of brushes.
All brushes should move freelyin the brush holders.
8. SOLENOID
TERMINALS
Bushings: If either the front or rear bushing show sign
of wear or damage, replace them. Bushing and rear
bracket are replaced as an assembly. Check armature
shaft thrust gapif rear bracket is replaced.
Remove front bushing by tapping bushing from inside
with a 7/16 inch tap. Do not remove cap from front
bracket.Threadcapscrew,samesizeastap,into
bushing. Using a slide hammer remove bushing from
front bracket. Press new bushing into front bracket. Us
care not to distort inside diameter
of bushing.
Brush Replacement Cut oldpositivebrushfrompigtail
at the brush.Be careful not to damage
field coil. Clean
1/4 to 3/8 inch (6.5 to 9.5 mm) of brush end of pigtail
with sandpaper or emery cloth. (Figure9).
Starter Mounting
Before installing starter motor. make sure the starter
mounting Surface on the engine base
is clean and free
of oil.
To installstarterusethefollowingprocedure.The
starter pinion gear lash does not require adjustment
1. Install starter motor and torque mounting capscrews
to that specifiedin ASSEMBLY TORQUES.
PIGTAIL
I
STILL ATTACHED
TO FIELD COIL
inch)
2. Connect battery cable and wires to starter. Connect
battery) cables to battery. Connect groundlast
cable
-SOLDER
MUST NOT
EXTEND BEYOND
BRUSHSURFACE
SMALL CHAMFER
REPLACEMENT
BRUSH
Push prepared end ofpigtail lead into holein replacement brush from the small chamfered side. Solder pigtail
lead to replacement brush on the large chamfered side,
using 50/50 tin/lead, rosin core solder and a standard
240/325 Watt soldering iron.Use a file to remove any
excess solder that may extend beyond brush surface.
Pigtail lead must not protrude from
surfaceon the solderedside ofbrush.
To prevent
stiffeningofpigtailleaddonotuseexcessive
amount of solder and heat.
Engine Disassembly
DISASSEMBLY/ASSEMBLY
Whencompleteenginedisassembly is necessary, first
remove all complete assemblies. Individual assemblies
such as fuelpumpandcarburetorcanbedisassembledgear.
and repaired at another time.
Suggested Disassembly Order
1. Drain crankcase.
2. Disconnect all exhaust and electrical lines.
3. Remove engine fromits mountings and place on a
suitable bench or work stand.
4. Remove all housings, shrouds, blower housings,
etc.
5. Remove flywheel, using a puller.
6. Remove ignitiontriggerandgearcover,being
careful to protectoil seal from keyway damage.
7. Remove crank gear, using a gear puller and ring.
8. Remove all accessories such as oil filter, starter,
intake manifold, fuel lines, spark plugs, etc.
9. Remove oil base, oil pump and cylinder heads.
10. Remove valves, springs,lifters, etc.
11. Remove camshaft and gear assembly.
12. Remove connecting rods and pistons.
13. Remove rear bearing plate, crankshaft, and front
bearing.
1. Useproperbearingdriverto
install frontmain
bearing after coatingit with alight film of oil.
2. Insertrearmainbearing in rearbearingplate.
3. Insertcrankshaft,rearbearingplate,andcrankshaft
4. Install pistons and connecting rods.
5. Installcamshaftandgearassembly;aligncrank
gear mark with cam gear mark.
6. Installvalveassemblies, oil pump, oil base,and
cylinder heads.
7. Install all accessories such asoil filter, starter, fuel
lines and spark plugs.
8. Install gear cover with oil seal, trigger ring, and
flywheel.
9. Check valve clearance.
10. Install all housings and air cleaner.
11. Fill crankcase with oil.
Operation
Start engine and check oil pressure. Run for approximately 15 minutes to bring engine tooperating
temperatures. Check for
oil leaks, fuel leaks, and exhaust
leaks. Adjust carburetor and governor for speed and
sensitivity.
Testing Compression
Thecompressiontester is used to determine the
condition of valves, pistons, piston rings and cylinders.
Keep all parts in their respective orders. Keep valve
To check compression:
to their respective
assemblies together. Return rod caps
1. Run the engineuntil thoroughly warm.
pistons. Analyze the reasons for parts failure.
2. Stop engine and remove spark plugs.
3. Remove air cleaner and place throttle and choke
in
Suggested Assembly Procedure
the wide open position.
4. Insert the compression gauge in one spark plug
Engine assembly is normally the reverse of the
dishole.
assembly procedure, observing proper clearances and
5. Crank the engine and note the reading.
torques. Use a torque wrench to assure proper tightness.
Coatthe internal enginepartswith oil as theyare
Refer toSPEClFlCATlONS for compression pressures.
assembled. After the internalengineparts
are
There may be variations due to equipment, temperatu
assembled, the engine should turn over by hand freely. atmospheric conditions and altitude. These pressures
Use only genuine Onan parts and special tools when
300
are for a warm engine at cranking speed (about
reassembling your engine.
rpm).
10-1
VALVE SYSTEM
Tappet Adjustment
The engine is equipped with adjustable valve tappets.
A properly functioning valve system
is essential for good
The valve tappet clearance should be checked and
engine performance.All engines utilize an L-head type
adjustedasspecified
in the PeriodicMaintenance
valve design as shown
in Figure 1. Access to the valve
Schedule (located in the Operator’s Manual). Adjust the system can be obtained by removing the cylinder heads
valve clearance only when engine
is at ambient temperand the valve covers on top of the
engine.
A valve
spring
ature. Proceed as follows:
compressor must be used to remove valves from the
cylinder block.
1. Remove ignition key to prevent accidental starting.
A valve stem seal is used on the intake valve guides.
2. Remove all parts necessary to gain access
to valve
Thissealmustbereplacedeachtimethevalve
is
tappets.
removed.
3. Remove spark plugs to ease the task
turning
of the
Place valves, springs, retainers, and tappets
in a rackas
engine over by hand.
they are removed from cylinder block so they can be
4. Place a socket wrench on the flywheel capscrew
identifiedandreinstalled
in theiroriginallocations.
and rotate the crankshaftin a clockwise direction
Discard old valve stem seals and replace with new ones
until the left intake valve (viewed from flywheel end)
during assembly.
opens and closes. Continue turning the crankshaft
until the TC mark on the flywheel
is lined up with the Use the following procedures to inspect and service the
valve system.
TC mark on the gear cover. This should place the
left piston (#1) at the topitsofcompression stroke.
Inspection
Verify that the left intake and exhaust valves are
closed and there
is no pressure on the valve lifters. Clean carbon from the valves, valve seats, valve guides,
and cylinder block.
5. The correct feeler gauge for the valve adjustment
(see S f EClFCATlONS)should pass freely between Valves: Check the valve face for evidence of burning,
valve cap (P216, P218, P220)or valve stem (P224)
warpage, out-of-round, and carbon deposits.
and tappet; a 0.002 inch (0.05 mm) thicker gauge
Burning and pitting are caused by the valvefailing to
should not (Figure 1).
seattightly.This condition is oftencausedbyhard
6. To correct valve clearance, use a7/16 inch open
carbon particleson the seat.
It may also be due to weak
end wrench to turn the adjusting screw to obtain valve
the springs, insufficent tappet clearance, warpage,
correct clearance. The screw is self-locking and
and misalignment.
will stay where it isset. A 9/16 inch(14 mm) open
end wrench is required to hold the tappet while
turning the adjusting screw.
7. To adjust valves on the right hand cylinder, turn
engine one complete revolution and againline up
mark on the flywheel and the TC mark on the gear
cover. Then follow adjustment procedure given for
left hand cylinder.
8. Replace all parts removed in Step 2. Tighten all
screws securely. Torque manifold bolts to specified
torque.
VALVE CLEARANCE
VALVE
VALVE STEM CLEARANCE
VALVE STEM
VALVE
CLEARANCE
VALVE ADJUSTING
VALVESEAT
INSERT
VALVE
GUIDE
VALVE
KEEPERS
VALVE
RETAINER
GUIDE
VALVE SEAT
INSERT
VALVE
VALVE
KEEPERS
VALVE RETAINER
VT-1035
FIGURE
1A.
INTAKE
VALVE
ASSEMBLY
- P216,P218,P220FIGURE1B.INTAKEVALVEASSEMBLY
10-2
- P224
Warpage occurs chiefly in the upper stem due to its
exposure to intense heat. Out-of-round wear follows
when the seatis pounded bya valve whose headis not
If a valve faceis burned
in line with the
stem and guide.
or warped, orif the stem is worn, install a new valve.
Drivlng out old guides can damage
thee guide or tappet bores. Be careful
not tostrike guide bores with driveror allow guide to
strike tappet bores during removal.
Valve Guide Installation Run a small polishing rod
guideto
Too much clearance
in the intake guide admits air and covered with crocus cloth through valve holes
oil into the combustion chamber, upsetting carburetion, clean ,out carbon and other foreign materials. Place a
increasing oil consumption, and making heavy carbon
new gasket on the intake valve guide, and coat the
cylinder
deposits. Carbon reduces heat dissipation. Clean metal edge of each new guide with oil. Place inguide
block and press in until guide protrudes 11/32 inch
is a goodheatconductorbutcarboninsulatesand
(8.7 mm) from valve box side of block. A suggested
retains heat This increases combustion chamber tempermethod of installationis shown in Figure 3.
atures which causes warping and burning.
Unburned carbon residue gums valve stems and causes
them to stick
in the guide. Deposits of hard carbon with
sharp points projecting become white hot and cause
pre-ignition and pinging.
ROD
or burned on an
Refinish valves that are slightly pitted
If valves are badly
pitted or have
accurate valve grinder.
a thin margin when refacing, replace them.
VALVE GUIDE
5/16-18 HEX,
(2 REQUIRED)
\
FIGURE 2. VALVE STEM AND VALVE GUIDEINSPECTiON
StemsandGuides: Always check valve stems and
gauge to measure
guidesfor wear (Figure2).Use a hole
the valve guide. When clearance with stem exceeds that
specified in DIMENSIONS AND CLEARANCESreplace
either valve or guide or both, as may be necessary.
Always regrind seat to makeconcentric with the newly
installed guide.
THREADED
ROD
Worn valve stem guides can be replaced from inside the
W-1023
valve chamber (a seal
is provided behind the intake
FIGURE 3. VALVE GUIDE INSTALLATION
valve guides only). The smaller diameter of the tapered
valve guides must face toward the valve head. Tappets
are also replaceable from the valve chamber after first Valve Stem Seals
(intake only):
Do not reuse valve stem
removing the valve assemblies.
seals. Each time the valves are removed from cylinder
seal must be used when valve
is reinstalled.
block, a new
Valve Guide Removal: Before removing valve guides,
use anelectric drill with a wire brush to remove carbon
not remove valveafter seal is
installed. valve
can
be withdrawn
and other foreign material from top surface of guides.
only as far as the groove in valve stem. Do not allow
Failure to perform this operation
may result in damage
to the guide bores. Drive the guides out with a hammervalve stemseal to come in contact with groove
or seal
and valve guide drive.
damage will result.
10-3
Valve Spring: Check valve springs for cracks, worn
Valve Seat Removal: Remove carbon and combustion
ends, distortion, and tension.If spring ends are worn,
depositsfromvalve seat Selectproperpullersize
check valve spring retainer for wear. Check for spring determined by inside diameter of valve seat On some
distortion by placing spring on a flat surface next to a pullers use a new seat as a guide
to adjust puller depth
square. Measure height of spring and rotateit against
(Figure 4). Puller jawsmust expandinto cylinder block
If distortion exceeds
square edge to measure distortion.
at the point where bottom of valve seat insert
rests on
0.06 inch (1.5 mm) replace spring. Check spring tension cylinder block. Position puller on valve seat and tighten
at theinstalledheight for both the valve open and closed
hex nut Clamp cylinder block to a solid bench. Attach
position using an accurate valve spring tester. Replaceslide hammer to puller. Tightenhex nut between each
or distorted.
any valve spring is
that
weak, cracked, worn,
blow with the slide
hammer.
ValveRotators: The P216, P218, and P220 engines use
free-rotating intake and exhaust valves. while in the
open position, the valves must rotate freely.
The P224 engine uses positive
type valve rotators on the
exhaust valves. When functioning properly, the valves
are rotated a fraction of a turn each time they open.
While in the open position, the valves must rotate freely.
There is no easy way to determine if a valve. rotatoris
be
good or bad. Onan recommends that valve rotators
replaced at each major overhaul or if a build up of
carbon is noted on valve face and valve seat.
Valve Seats: Inspect valve seat inserts. If seats are
loose, cracked or severely pitted, new ones must be
installed. Remove valve seat inserts using a valve seat
bores in cylinder block
removal tool.If valve seat insert
are damaged or worn so that a press fit cannot be
obtained when installing new standard size valve seat
inserts, the bores must be machined for an oversize
seat
VALVE SEAT
INSERT DRIVER
(USE PROPER TOOL)
VALVE
K THIS SURFACE
BURRS BEFORE
INSERTINGSEAT
USE NEW VALVE SEAT TO
ADJUST PULLER DEPTH
FIGURE
5. INSERTING NEW VALVE SEAT
Valve Seat Installatlon: After the old seat has been
removed, clean outany carbonor metal burrs from the
seat insert recess. Use a valve seat insert driver and
hammer to install the insert (Figure5). Drive the valve
i so the insert enters the recess evenly.
seat insert n
Make certain that the valve seat insert rests solidly on
the bottom, of the recess all the way around its
circumference.
To assure a tight valve seat fit and eliminate the danger
of seatloosening in the bore, valve seat must be staked.
PULLER JAWS
FIGURE 4. VALVE SEAT REMOVAL
Insert valve: seat staker into valve seat ,or guide in
cylinder
lead
block.
Using
a
hammer,staking
strike
the
tool a sharpblow to wedge new valve seat securely in
place. It will be necessary torefinish valve seat inserts
before
installing
valves.
10-4
TAPPETS
Very little wear takes place on tappet diameters orin
tappet bores. If the clearance between tappet and bore
in cylinder block exceeds specifications, replace the
tappet.
Inspect the tappet faces which contact camshaft
lobes
for roughness, scuffing, or concave wear. Replace any
worn tappets. If tappets are worn, inspect camshaft for
wear.
VALVE FACE AND SEAT GRINDING
Before installingnew valves or previously used valves,
If used
inspect valve seats for proper valve seating.
cleaned
valves are reinstalled, the valve stemsbeshould
and valve faces ground to their specified angles
44°. of
Refinish valve seats to a
45° angle. When refacing
valves and seats, remove all evidence of pitting and
grooving. If end of valve stemis pitted or worn, true
it and
clean it up on the refacer wheel. A very light grind is
usually enough to square
stem and remove any pits or
be thoroughly cleaned.If
burrs. The valve guide should
valve guideis worn, or valveis warped, the necessary
parts must be replaced.
Refinish valve facesto a 44° angle on avalve refacing
machine. The firstcut from valve face must be a light
grinding. Checkif there is an unevenness of metal being
removed. If only part of valve's face has been touched,
if valve is properly seatedin machine orif
check to see
valve is warped, worn, or distorted. When cut is even
around the whole valve face, keep grinding
until complete face is ground clean. Be sure the correct valve
is warped, a
face angleis maintained. When valve head
knife edge will be ground (Figure
7) on part orall of the
head due to the large amount of metal that must be
Heavy valve heads
removed to completely reface valve.
are required for strength and good heat dissipation.
Knife edges lead to breakage, burning, and pre-ignitio
edge.
due to heat localizing on the
Replace any valve that cannot be entirely refaced whi
keeping a good valve margin (Figure7 ) or is warped,
worn, or damagedin any way. The amountof grinding
necessaryto true a valve indicate whether valve head
worn or warped.
WARPED
VALVE WITH
EDGE
KNIFE
EDGE
KNIFE
By grinding the valve face and seat at slightly different
angles,afine
line of contactonfaceandseat
is
obtained, eliminating the need tolap the seating surfaces. The one degree difference
in angles is defined as
the interference angle (Figure 6). The seat angle is
greater than that of the valve face. This assures contact
at the maximum diameter
on valve seat seating surface.
GOOD MARGIN
T
FIGURE 7. VALVE HEAD MARGIN
When new valve seats are installed, or previously use
seats reground, refinishingmust be done with a valve
seat grinderusedaccordingtothemanufacturer's
directions.
Valve seats should be ground with a 45 degree stone
and the widthof the seat band should be
1/32 inch to
3/64 inch (0.8 to 1.2 mm) wide. Grind only enoughto
assure proper seating.
Place each valve in its proper location. Check each
valve for a tight seat. Make several marks at regular
intervals across the valve face using machinist's b
is
Observe if the marksrub off uniformly when the valve
rotated part of a turn -against the
seat. The valve seat
shouldcontactthevalvefaceevenly at all points. The
line of contactshouldbe atthecenterofthevalveface.
FIGURE 6. VALVE
INTERFERENCE
ANGLE
10-5
GEAR COVER
FLYWHEEL
Removing the flywheel
is a relatively simple process, but After removing the mounting screws, tap the gear cover
thefollowingprocedure must be followedtoavoid
gently with asoft faced hammerto loosenit.
damage to the gear case and possible
injury to the
operator.
When installing the
gear cover, make sure pin
thein the
gear cover engages the nylon lined (smooth)
in thehole
1. Turn the flywheel mounting screw outward about
governor cup. Turn the governor so
cup
the nylon lined
two turns.
Use a small amount
hole is at the three o’clock position.
of grease to assistin holding governor cupin position.
DO not removethe screw comThe smooth side of the governor yoke must ride agains
pletelysinceitactsasarestrainer
the governor cup. Turn the governor arm and shaft
when the flysheel snaps loose. If the flywheel is
clockwise as far as possible and holdin this position
not held by the screw, the spring action in the
until thegearcover
is installedflushagainstthe
wheel will cause to fly off with greatforce which
oil
crankcase. Be careful notto damage the gear cover
can cause injury to the operator.
s e a l (Figure 9).
n
2. Install a puler bar on the flywheel (Figure 8).
MOUNTING SCREW
ROTATE GOVERNOR
PIN FITS
CUP SO
INTO THE METAL
BUSHING IN THE CUP
FIGURE
BLOWER WHEEL PULLEY
I
GOVERNOR CUP
GOVERNOR
3. Turn the puller bar b o l t s in, alternately, until the
wheel snapsloose on the shaft.
DO notuse a screwdriver or
similar tool or pry behind the
flywheel against the gear case. The gear case
cover is die-cast material andwill break if undue
pressure is applied in this manner.
IF FEELER
4. Unscrew the puller from the flywheel, remove the
flywheel mounting screw and washer and
pull the
flywheel off the shaft. Take care not to drop the
wheel. A bent or broken fin will destroy the balance.
ENTER HOLE
BALL HAS
FIGURE 9. GEAR COVER ASSEMBLY
THE
DIMENSION S H O W N
O N DRAWING WILL
A S INDICATED
CENTER PIN
SNAP
BALL GOVERNOR
GOVERNOR CUP
FIGURE
BALL GOVERNOR
GOVERNOR CUP DETAILS
GOVERNOR CUP
With the gear cover removed, the governor
cup can be
taken off after removing the snap
ring from the camshaft
center pin. Catch the flyballs while sliding the
cup-off
(Figure 10).
TIMING GEARS
If replacement of either the crankshaft gear or the
camshaft gear becomes necessary, always install both
gears new.
The camshaft and gear be
must
replaced as an assembly.
Beforeremovingthecamshaftandgearassembly,
Replace with a new any
partflyball which is grooved
or
remove the cylinder head and valve assemblies.
has a flat spot; theball spacer if its arms are worn or
otherwise damaged; thegear/spacer assembly if loose
on gear hub, and the governor
cup if the race surface is To remove the crankshaft gear, first remove the snap
ring and retainer washer, then attach the gear pulling
grooved or rough. The governor cup must be a freering using two No. 10-32screws (Figure 11). Tighten
spinning fit on the camshaft center pin,
but without any
the screws alternately
until both aretight. Attach a gear
excessive play.
puller to the pullerring and proceed
to remove the gear.
tilt the engineso the
When installing the governor cup,
near the edge. The
Each timing gear is stamped“O”
with
gear is up, put the flyballs in place (Figure 10), and
gearteethmustmesh
so thatthesemarksexactly
install the cup and snap
ring on the center pin.
coincide when the gears are installed in the engine.
When installing the camshaft gear and shaft
assembly,
The camshaft centerpin extends out3/4 inch (19 mm)
be sure the thrust washer is properly
in place behind the
from the end of the camshaft. This distance provides an
camshaftgear.Then install the crankshaft retaining
in-and-out travel distance
of 7/32inch (5.6 mm) for the
washer and lock ring.
governor cup, as illustrated. Hold the cup against the
flyballs whenmeasuring.Thecamshaftcenterpin
damage.
cannot be pulled outward or removed without
If the center
pin extends out too far,cup
thewill not hold
the flyballs properly. If the distance less
is than 7/32”
(5.6 mm), the engine will race, especially at no load.
Remove the centerpin and press
in a new pin.
CRANKSHAFT
4. Turn the crankshaft until the piston
is at the bottom
rod nuts. Lift
of itsstroke and remove the connecting
the rod bearing cap from therod and push therod
and piston assembly out through the top
of the
cylinder using hammer
a
handle.Do not scratch the
crankpin andcylinderwallwhenremovingthe
piston androd.
GEAR PULLER
5. Mark each piston and
rod assembly so they canbe
returnedto their respective cylinders after overhaul.
Keep connecting rod bearing caps with their
respectiverods.
6. Remove the piston rings from the piston with a
piston ring spreader (Figure 13). Remove the piston
pin retainer and push the piston
pin out
E MARKS
WHEN
ING TIMING
EARS
FIGURE 11. TIMING GEARREMOVALAND INSTALLATION
PISTONS AND CONNECTING RODS
Observethe following procedure when removing pistons
and connectingrods from the engine.
1. Drain oil.
2. Removethe cylinder head and
oil base pan from the
engine.
3. Remove the ridge from the top of each cylinder with
a ridge reamer before attempting piston removal
(Figure 12).
Forcingthepistonfromthe
cylinder before reaming may
cause damage to the piston lands and
break rings.
FIGURE 13. REMOVING PISTON RINGS
7. Remove dirt and deposits from the piston surfaces
with an approved cleaning solvent Clean the piston
or the end ofa
ring grooves with a groove cleaner
piston ring filed to a sharp point (Figure14). Care
must be taken not to remove metal from the groove
sides.
pistions. Therematerialswill causepiston damage.
8. Cleanthe connecting rodsin solvent. Blow outall
passages with compressed air.
P224
FIGURE 12. REMOVINGRIDGE FROM CYLINDER
Engines that have been filled with
0.005 inch (0.13 mm)
oversize pistons at the factory are identified by the le
E after the serial number. Number is stamped on the
cylinder block and on the unit nameplate.
10-8
FIGURE 15. CHECKING RING SIDE CLEARANCE
have deep nicks, signs of fractures, scored bores,
bores with dimensions which exceed that specified
in DIMENSIONSAND CLEARANCES.
Measuring Pistons:
1. Proper piston tolerances must be maintained
for satisfactory operation.
k
FIGURE 14. PISTON GROOVE CLEANING
Refer to DIMENSIONS AND CLEARANCES to
determine where to measure piston be
to sure
the total clearance follows specifications.
Follow the procedures given below when inspecting
pistons and connectingrods.
Piston Inspection:
1. Inspect the pistonsforfracturesat
the ring
lands, skirts andpin bosses. Check for wear at
the ring lands using a new ring and feeler gauge
(Figure 15). Replace the piston when the
side clearance of the top compression ring
reaches that specified in DIMENSIONSAND
CLEARANCES.
2. Replacepistonsshowingsignsofscuffing,
scoring, worn ring lands, fracturesor damage
wear near the
from preignition. Excessive piston
edge of the topring land indicates preignition.
Connecting Rod Inspection:
Replace connecting rod bolts and nuts that have
damaged threads. Replace connecting rods that
10-9
FIGURE 16. MEASURINGPISTONCLEARANCE
Measuring PistonRings:
1. Install the piston
ring in the cylinder bore. Invert
the piston and push the
ring to the endof ring
travel, about halfwayinto the bore, which trues
the ring end gap. Check the gap with a feeler
gauge (Figure17).
After removing pistons, crankshaft, cylinder heads, etc.,
inspect block for cracks and
wear. If block is still serit for
cleaning
as
follows:
viceable,
prepare
1. Scrapeall old gasket material from block. Remove
oil by-'pass to allow cleaning solution to contact
inside of oil passages.
2. The practice of filing ring ends to increase the
end gapis not recommended.If the ring end gap
does not meet specifications, check corfor the
r e c t set of rings and the correct boresize. A
cylinder bore that
is 0.001 inch (0.03mm) under
size will reduce the end gap 0.003 inch (0.08
mm).
2. Remove grease and scale from cylinder block by
agitating in a bath of commercial cleaning solution
or hot soapy washing solution.
3. Rinse block in clean hot waterto remove cleaning
solution.
When rebuilding the engine, thoroughly inspect block
for any condition that would itmake
unfit for further
use.
This inspectionmust be made after
all parts have been
removed and block has been thoroughly cleaned and
dried.
1. Make
a
thorough check for cracks. Minute cracks
may be detected by coating the suspected area with
a mixture of 25 percent kerosene and 75 percent
light motor oil. Wipe the part dry and immediately
apply a coating of zinc oxide (white lead) dissolved
in wood alcohol. If cracks are present, the white
coating will become discolored at the defective
area. Always replace a cracked cylinder block.
2. Inspect all machined surfaces and threaded holes..
Carefully remove any
nicks or burrs from machined
surfaces. Clean out tapped holes and clean up any
damaged threads.
3. Check topof block for flatness with a straight edge
and a feeler gauge.
Cylinder Bore Inspection: Inspect cylinder bores for
scuffing, scratches, wear, and scoring.
If cylinder bores
are scuffed, scratched, worn, or scored, they must be
rebored and honed for the next oversize piston.
FIGURE 17. POSITIONING OF PISTONRING
AND MEASURINGOF END GAP
When the appearance of cylinder bores is good and
there arenoscuff marks, check cylinder bore foror wear
out of roundness as follows:
CYLINDER BLOCK
1. Check cylinder bore for taper, out of round, and
wear with a cylinder bore gauge, telescopic gauge,
The cylinder block
is the main support all
forother basic
or inside micrometer. These measurements should
Crankshaft and camshaft are supported by
engine
be taken at four places: top and bottom of piston r
the block, assuring alignment of the crankshaft and
travel, parallel and perpendicular to axis
of crankcylinder bores.
shaft (Figure18).
parts.
10-10
2. Record measurements taken at top andbottom of
piston travel as follows:
A Measure and record as “ A the cylinder bore
diameter (parallel to crankshaft) near the top of
cylinder bore.
B. Measureand record as “B’ cylinder bore
diameter (parallel to crankshaft) at the bottom of
piston travel.
RING
WEAR
AREA
C. Measureand record as “C” cylinder bore
diameter (perpendicular to crankshaft) near the
top of cylinder bore.
D. Measure and record as “D” cylinder bore
diameter (perpendicular to crankshaft) at the
bottom of piston travel.
E.
Reading “A” subtracted from reading “B” and
reading “C” subtracted from reading “D” indicates cylinder taper.
If cylinder taper exceeds that specified in
DIMENSIONS AND CLEARANCES rebore and
hone cylinder to the next oversize.
F. Reading “ A comparedtoreading
“C“ and
reading “B” compared to reading “ D indicate
if out of
whether or not cylinderis out of round.
round exceeds that specified in DIMENSIONS
ANDCLEARANCES the cylinders must be
rebored and honed to the next oversize.
Reboring the Cylinder
FIGURE 18. METHODS OF MEASURING THE DIAMETER
OF A CYLINDER BORE
Rebore and hone engine whenever cylinder bore is
worn,damaged,outofround,
or if cylindertaper
A worn cylinder bore should be
exceeds specifications.
resized to the smallest standard oversize diameter at
which it will-cleanup. Thefinal finish and bore diameters
should thenbe obtained by honing. Final bore diameter
shouldequalthestandarddiameteraddedtothe
oversize.
After boringtothe
correct oversizecylinderbore
dimensionpistonandringclearanceshouldbe
appropriate. There is no needto adjustor “fit” pistons
and rings.
When reboringcylinders,takethefollowingprecautions:
If boring bar is operated incorrectly,
1. Make sure cutting tool is properly ground before
it will produce a rough cylinder
using it.
surface that may not clean up even when honed. Boring
should be done only by qualified service personnel
2. Be sure top of engine block is smooth and deposit
who are careful in their work.
free.
10-11
DeglazingCylinder Bores
Deglaze the cylinder bores
ifthere are noscuff marks
andnowear or out of round beyond specifications
before installing new rings. Deglazing gives a fine finish,
4. Make aninitial rough cut, followed by a finish cut.
but doesnotenlarge cylinder diameter,so the original
Then hone cylinder bore to the specified oversize. pistons with new rings may
still beused.
3. Cleanbaseofboringbarbeforebar
is setup.
Deposits under boring
bar will cause toit tilt and the
cylinder will be distorted after boring.
a
The reason for dealazing
a cylinder is to provide cavities
Honing
Cylinders
(Using
Precision
Hones)
to
hold oil
during
piston
ring
break-in.
Refer to hone manufacturer's recommended
grit size to
1. Wipe cylinder bores with a clean cloth which has
produce specified surface finish of 20 to 40 RMS. Too
in clean, light engine oil.
rough of a finish will wear out the rings and too smooth been dipped
of a-finish can retard piston
ring seating.
2. Use a brushtype deglazing tool with coated bristle
1. Position block solidly for either vertical or horizontal tips to produce a crosshatch pattern
in the cylinder
a drill press
or
heavy-duty
drill
bore.
honing.
Use
either
250 to 450 rpm.
which operates at approximately
3. Use a slow speed drill to drive the deglazing tool.
in cylinder (10 to
2. Follow hone manufacturer's instructions for the use Move deglazing tool up and down
12 completestrokes)rapidlyenoughtoobtaina
of oil or lubricanton stones. Do notuselubricants
with
19).
in bore and adjust stones to fit snugly to
3. Insert hone
the narrowest section. When adjusted correctly, the
or chatter in cylinder bore,
hone should not shake
is not
but will drag freely up and down when hone
running.
4. Connect drill to hone and start drill.
Feel out bore for
high spots, whichcauseanincreaseddragon
stones. Move hone up and down
in bore with short
overlappingstrokesabout 40 timesperminute.
Usually bottom of cylinder must be worked out first
because it is smaller. As cylinder takes a uniform
diameter,movehoneupanddown
all theway
through cylinderbore.
5. Check diameter of the cylinder regularly during
AVOID THIS FINISH
is the easiest method but PRODUCECROSSHATCHSCRATCHES
honing. A dial bore gauge
FOR FAST RING SEATING
a telescoping gauge can be used. Check size at six
places in bore: measure twice at top, middle and
FIGURE 19. CROSSHATCHING
bottom at 90-degree angles.
Never use gasoline or commercial cleaners to clean cylinder
bores after deglazing or honing. These solvents
will not remove abrasives from the walls. Abrasives not removedfrom engine will rapidly wear
rings, cylinder walls, and bearing surfacesof all
lubricated parts.
6. Crosshatch formed by the stones should form an
included angle
of 23degrees.This can be achieved
(250 to 450 rpm) up and
by moving the rotating hone
down in cylinder bore about40 times per minute.
7. Clean cylinder bores thoroughly with soap, water
A cleanwhiteragshouldnot
andcleanrags.
become soiled on wall after cleaning is complete.
Do not use a solvent
or gasoline since they wash
oil
from the walls but leave the metal particles.
8. Dry crankcase and coatit with oil.
4. Clean cylinder bore thoroughly with soap, water
and clean rags. Continue cleaning until a clean
white rag shows
nodiscoloring when wiped through
cylinder 'bore.
10-12
CRANKSHAFT
Clean crankshaft thoroughly and inspect journals for
scoring, chipping, cracking, or signsof overheating. If
crankshaft has overheated, is scored, or excessively
worn, reconditioning or replacement will be required.
Examine bearing journals for cracks
if overheating has
occurred.
Measure crankshaft main bearing and connecting rod
to check for
journals at several places on their diameter
roundness and taper.
The only recommended method of reconditioning the
crankshaft is regrinding, as requiredto accommodate
undersize bearings. Metalizing of bearing journals
is not
recommended.
FRONT CAMSHAFT BEARING
If regrinding of crankshaft journals is necessary, the
work should be done by a reputable machine shop that
to handle precision work of this
has suitable equipment
type. Undersize main bearings and connecting rodsare
available.
PRESS BEARING
0.50 (12.7 mm)
Whenever making major repairs on the engine, always
inspect the drilled passages of the crankshaft. Clean
themtoremoveanyforeignmaterialandtoassure
proper lubrication of the connecting rods.
BEARINGS
REAR CAMSHAFT BEARING
With camshaft and crankshaft removed, use a microFIGURE 20. CAMSHAFT BEARINGS
meter to measure diameter of bearing journals. Use a
dial bore gauge or a telescopic gauge and micrometer
to
to measureinsidediameterofbearings.Refer
DIMENSION AND CLEARANCESto determineif clearNew crankshaft main bearings are precision type whic
ances are within specifications.
do not require line reaming or line boring after installation.Useapressorasuitabledriver
to remove
Any bearingthatisscored:chipped,pittedorworn
bearings. Support casting to avoid distortion and to
avoid damaging the bearing bore during removal and
beyond the specified limits must be replaced.
installation.
Removal of the camshaft bearings requires complete
Before installing main bearings, expand bearing
by bore
disassembly of the engine. Use a press or a suitable
placing the casting
in an oven heated
driver to remove bearings. Support casting
to avoid
to 200°F (94°C).
If
distortionandtoavoiddamagingthebearingbore
practical, cool the precision bearing
to shrink it.
during removal and installation.
Before installing the front main bearing, use the tow
Replacementcamshaftbearingsareprecisiontype
included with the bearing
kit to clean the outside
of the
which do not require line reamingor line boring after
bearing and bearing bore
in the block.
installation. Clean outside of the bearing and bearing
bore in the block. Before installing cam bearings use
Breathing vapor from towelette and
Locktite Bearing Mount on outside diameter of bearing.
prolonged contact with skin can be
Use a combination bearing driver to install bearings.
harmful. Be sure area is well ventilated.
Place the bearing on the crankcase over the bearing
bore with the lubricating hole (front only)
in the proper
position. Be sure to start the bearing straight. Pressin
thefrontbearingflushwiththeoutsideend
ofthe
bearing bore. Front cam bearingoil hole must line up
with oiling hole in cylinder block (Figure 20). Press in
therearcamshaftbearing
to thedimensionshown
(Figure 20). Lubricate bearing surfaces with oil after
installing.
10-13
Afterallowing three to four minutes for drying, apply
the Locktite from the small tube to the matingofsurface
the bearing and the bearing bore. Align oil
theholes in
thebearingwiththe
oil holesinthebearingbore
(Figure 22). The oil passage should be at least half open.
Installthebearingflushwiththeblock,usingthe
off excess Locktite around the
combination driver. Wipe
bearing. Allow at least one hour for hardening
at room
temperature.
In the rear bearing plate, install the bearing flush
to
1/ 6 4 inch (0.40 mm) below theend of the bore.
Be sure
to align the
oil holes in the bearing with the
oil holes in
the bearing bore (Figure
21). The oil passage must be at
least halfopen. Lubricate bearing after installation.
If head of lockpin isdamaged, use side cutters
or Easy
Out tool to remove and install new pin. Oil grooves in
thrust washers must face the crankshaft, and washers
each washer
must be flat (not bent). The two on
notches
must fit over thetwo lock pins to prevent riding on the
crankshaft (Figure21).
FIGURE 21. BEARINGS FOR REAR BEARING PLATE
Engines shippedfrom the factory have separate thrust
washers and main bearingsfor both front andrear of
engine. Front bearing replacement part
is a one piece
bearing(withattachedthrustwasher)asshown
in
to this
Figure 22. Do not add an additional thrust washer
front bearing.
FROM MAIN
Lubricate the front main bearing lightly with oil and
insert the crankshaft. With the rear bearing plate gasket
in place and the rear plate bearing lubricated, slide the
thrust washer (grooves toward crankshaft) and plate
A light filmof oil on the
over the end of the crankshaft.
thrustwashermay
hold it in placewhileinstalling
bearing plate over crankshaft.
Lineup notches of thrust
washer with lock pins before tightening end plate or
lock pinswill be damaged.
CRANKSHAFTENDPLAY
After the rear bearing end' plate has been tightened,
using the torque recommended
in ASSEMBLY TORQUES
AND SPECIAL TOOLS, check the crankshaft endplay
(see DI(Figure 23). If there is toomuchendplay
MENSIONS ANDCLEARANCES for minimum and
maximum endplay), remove the rear bearing end plate
and add a Shim (Figure21) between the thrust washer
and plate. Reinstall the end plate, making sure the thrus
washer and shim- notches line up with the lock pins.
Torque and recheck endplay of the crankshaft.
FIGURE 23.
CRANKSHAFT ENDPLAY
I
CHECKING CONNECTINGROD BEARING
CLEARANCE WITH PLASTIGAUGE
1. Make certain that all parts are marked or identified
so they are installed
in their original positions. Using
a clean dry cloth, thoroughly clean
all oil from
rod. If connecting
crankshaft journal and connecting
rod bearing inserts are being replaced (P224 only),
install them in rod and cap.
2. Place a piece of correct size Plastigauge in the
bearing cap the
full width of the journal surface and
about 1/4 inch (6.35mm) off center (Figure24).
3. Rotate the crankshaft about
30degrees from bottom
dead center and reinstall the bearing
cap; tighten
rod bolts to the torque specified in ASSEMBLY
TORQUES AND SPECIAL TOOLS. Do not turn the
crankshaft.
4. Remove bearing cap. The flattened Plastigauge
will
be
found
adhering
to
either
the
bearing
cap
or
crankshaft.
5. Compare flattened Plastigauge with the graduations
on Plastigauge envelope to determine clearance.
FIGURE 24. MEASURING
BEARING
CLEARANCE
OIL SEALS
The bearing plate mustbe removed to replace theoil
The number within the matching graduation on the seal (Figure
25). Drive the oil seal out from the inside.
envelope indicates total clearance
in millimetersor
thousandths
inch.
anof
Before
installing
seals,fill the space
between
lips with
a
multi-purpose grease. Thiswill improve sealing.
When, installing thegear cover oil seal, tap the s e a l
inward until it is .645 inch (16.4 mm) from the front of the
gear cover.
When installing the bearing plate oil s e a l , tap the s e a l
into thebearingplatebore
to bottomagainstthe
or place
shoulder in the plate bore. Use a seal expander
a piece of heavy paper around the end of the cranksha
when replacing the bearing plate to avoid damaging
seal. Removethe paperas soon as the plateis inplace.
REAR BEARING PLATE
SURFACE SHOULD BE
CLEANED OF ALL OLD
SEALING COMPOUND
BEFORE INSTALLING
MOUNTING FACE
OF GEAR COVER
OR PRESS
SEAL TO SHOULDER
OF THE PLATE BORE
'
GEAR COVER
GEAR COVER SURFACE
SHOULD BE CLEANED OF ALL
OLD SEALING COMPOUND
BEFORE INSTALLING SEAL
REAR BEARING PLATE
OIL SEAL
GEAR COVER OIL SEAL
FIGURE 25. GEARCOVERAND REAR BEARING PLATE OIL SEALS
10-15
P216, P216, P220
Install one fastener and tighten to 5 ft-lbs (7 Nm).
Repeat this for the other fastener. Tighten both
fasteners down to the torque specified in ASSEMBLY
TORQUES.
PISTON ASSEMBLY
1. Lubricate all parts with engine oil.
2. Position piston on its respective rod and install the
pin.
P224
Install and tighten the nuts evenly in steps, to the
torque specified in ASSEMBLY TORQUES.
3. Install the rings on the pistons starting with the oil
control ring (Figure 26). Use a piston ring spreader
to prevent twisting or excessive expansion of the
ring. Compression rings have a dot or the word
“top” on one side of the ring to indicate w,hich side
faces the top of the piston. Unmarked piston rings
can be installed either way. The oil control ring has
an expander; install the expander first and then
close until the expander ends butt. The joint should
be 160 degrees from the gap of that ring.
OIL HOLE * OR
* OIL HOLE NOT USED, LATER PRODUCTION
COMPRESSION RINGS
P216, P212, P222 CDNNECTING ROD
CT-la7
P224 CONNECTIND ROD
OIL RING
\
EXPANDER
CT-1047
FIGURE 26. PISTONRINGS
INSTALLATION
OF PISTON IN CYLINDER
1. Turn the crankshaft to position the number one rod
bearing journal at the bottom of its stroke.
CT-loa
FIGURE 27. INSTALLING PISTON AND
CONNECTING ROD
2. Lubricate the number one piston assembly and
inside of the cylinder. Compress the rings with a ring
compressor (Figure 27).
5. Install the remaining piston and rod in the same
manner. Crank the engine over by hand to see that
all bearings are free.
3. Position the piston and rod assembly in the cylinder
block. Oil squirt hole of connecting rod must face
camshaft.
6. Install the oil base with a new gasket.
7. Install the cylinder heads. See Cylinder Headsection
for torques and torquing procedure.
4. Tap the piston down into the bore with the handle
end of a hammer until the connecting rod is seated
on the journal (Figure 27). Install the bearing cap on
the rod.
6. Replace oil and break in engine.
lo-16
CYLINDER HEADS
3. Use
new
head
gaskets
and
clean
both
heads
the
and the cylinder block thoroughly where the head
Remove
the cylinder
heads
for
carbon
cleaning
and
gaskets
rest.
gasket change at intervals specified
in the Periodic
MaintenanceSchedule (located in theOperator's
Manual).
1. Use a 1/2 inch (13 mm) socket wrench to remove
cylinder headbolts or nuts. Lift headsoff.
(37°C) beforeremoval. At temperatures above
100° F (37° C), the gasket will become gummy a d
difficult to remove from the surface of the block
a d cylinder head.
2. After removing heads, clean all
outcarbon deposits.
Be careful not todamage the outer sealing edges
fit. The heads are made
of aluminum
where gaskets
and canbe damaged by careless handling.
P216, P218, P220 Installation
1. Place a head gasket on the cylinder block and alig
the holesin the gasket with the holes
in the cylinder
block While holding the gasket against the cylinde
head,carefullyinstallthecylinderheadonthe
bolts
engine. Do notattempttoslidethehead
through the gasket without the cylinder block behind
it or the gasket may tear.
2. Follow the head torque sequence shown
in Figure
28. Tighten all bolts to 5 ft-lbs (7 Nm), then10 ft-lbs
(14 Nm), then to the torque specified
in ASSEMBLY
TORQUES. Recheck all head bolts forcorrect
torque.
NO. 2 CYLINDER (RH)
NO. 1 CYLINDER(LH)
FIGURE 28. CYLINDER HEAD TORQUESEQUENCE
10-17
P224 Installation
1. Place a head gasket on the cylinder head and alignengine damage.
the stud holes in the gasket with the instud
the holes
cylinder head. While holding the gasket against the3.
cylinder head, carefully install the cylinder head on
the engine. Do not attempt to slide the gasket over
the studs without the cylinder head behind
it or the
gasket may tear.
Follow the head torque sequence shown in Figure 30. Tighten all nuts to 5 ft-lbs (7 Nm),then
10 ft-lbs (14 Nm), then to the torque specified in
ASSEMBLY TORQUES. Recheckall nuts for correct
torque.
2. Install a flat
washer, two compression washers, and
nut on each
of the topsix studs (Figure29 for correct sequence). When properly installed, only the
outside edges of the compression washers
will be in
contact with each
other. Install a flat
washer and nut
on eachof the four bottom studs.
HEAT TREATED
NUTS
COMPRESSION
WASHERS
NO. 1 CYLINDER
6 LONG STUDS/HEAD
FIGURE
4 SHORT STUDS/HEAD
30.
NO. 2 CYLINDER
CYLINDER HEAD TORQUE
SEQUENCE
4. Recheck torque when the engine has run aof total
FIGURE
29.
50 hours.
CYLINDER HEAD WITH COMPRESSIONWASHERS
10-18
I
Product information andspecificationsare
shown herein as of thetime of printing.
Wheel Horse Products, Inc. reserves the
right to change productspecifications.
designs and standard equipment without
noticeand without incurring obligation.