Page 1
Service Manual
,29389629 -2942:
+*/&&$
1867954 67 3$2$,
+*(:%)%%-
&'#%%
Page 2
##
The engine exhaust from this product
contains chemicals known to the State
of California to cause cancer, birth
defects or other reproductive harm.
2
Page 3
.0 152 83 (87;27;:
SECTION TITLE PAGE
SAFETY PRECAUTIONS iii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. General Information 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
About this Manual1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Model Number1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Obtain Service1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Performance Curve1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.Specifications 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Performer OHV220 Engine Specifications2-1. . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensions and Clearances2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ElectricaL Specifications2-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Assembly Specifications2-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine oil Recommendation 2-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque Specifications2-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.Engine Troubleshooting 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4. Engine Systems 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lubrication System 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel System 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Carburetor4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Charging System 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting System 4-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5. Engine Disassembly 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.Engine Reassembly 6-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Precautions6-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools6-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Break–In Operation 6-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pre-Assembly6-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Re-assembly Procedures6-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Final Checks6-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
i
Page 4
Safety Precautions
Thoroughly read the OPERATOR’S MANUAL be-
fore operating the engine. Safe operation and top
performance can be obtained only with proper
operation and maintenance.
The following symbols in this Manual alert you to po-
tential hazards to the operator, service person and
equipment.
alerts you to an immediate hazard
which will result in severe personal injury or
death.
WARNING
practice which can result in severe personal
injury or death.
CAUTION
practice which can result in personal injury or
equipment damage.
Electricity, fuel, exhaust, moving parts and batteries
present hazards which can result in severe personal
injury or death.
alerts you to a hazard or unsafe
alerts you to a hazard or unsafe
GENERAL PRECAUTIONS
• Keep ABC fire extinguishers handy.
• Benzene and lead in some gasolines have been
identified by some state and federal agencies as
causing cancer or reproductive toxicity. Do not to
ingest, inhale or contact gasoline or its vapors.
• Do not work on the engine when mentally or
physically fatigued or after consuming alcohol or
drugs.
• Carefully follow all applicable local, state and
federal codes.
WARNING
tended for use in aircraft. Such use can lead
to engine failure, severe personal injury or
death.
This engine is not designed or in-
FUEL IS FLAMMABLE AND EXPLOSIVE
• Keep flames, cigarettes, sparks, pilot lights,
electrical arc-producing equipment and switches
and all other sources of ignition well away from
areas where fuel fumes are present and areas
sharing ventilation.
• Do not fill the fuel tank while the engine is run-
ning.
• Make sure all fasteners are secure and torqued
properly.
• Keep the engine and its compartment clean. Ex-
cess oil and oily rags can catch fire. Dirt and gear
stowed in the compartment can restrict cooling
air.
• Before working on the engine, disconnect the
negative ( – ) battery cable at the battery to prevent starting.
• Use caution when making adjustments while the
engine is running—hot, moving or electrically
live parts can cause severe personal injury or
death.
• Used engine oil has been identified by some
state and federal agencies as causing cancer or
reproductive toxicity. Do not ingest, inhale, or
contact used oil or its vapors.
• Fuel lines must be copper or steel tubing or pip-
ing, adequately secured and free of leaks.
• Use approved flexible fuel hose for connections
at the engine. Do not use copper tubing as a flex-
ible connector—vibration will cause it to work-
harden and break. Use non-conductive hose if
the fuel line could become a path for cranking
current.
• LPG leaks into an inadequately ventilated space
can lead to explosive accumulations of gas. LPG
sinks when released into the air and can accumulate inside basements and other below-grade
spaces. Precautions must be taken to prevent
gas leaks and the accumulation of gaseous fuel
in the event of a leak.
• The fuel line must have a manual shutoff valve
unless the highest fuel level in the supply tank is
lower than the connection at the engine.
ii
Page 5
ENGINE EXHAUST IS DEADLY!
• Learn the symptoms of carbon monoxide poi-
soning in this Manual.
• Inspect the exhaust system every time the en-
gine is started and after every eight hours of operation. If the exhaust noise changes, shut down
the engine immediately and have it inspected.
• The integral exhaust system must not be modi-
fied in any way.
• Do not use engine cooling air to heat a room.
BATTERY GAS IS EXPLOSIVE
• Wear safety glasses and do not smoke while
servicing batteries.
• When disconnecting or reconnecting battery
cables, always disconnect the negative ( – ) bat-
tery cable first and reconnect it last to reduce arc-
ing.
MOVING PARTS CAN CAUSE SEVERE
PERSONAL INJURY OR DEATH
• Do not wear loose clothing or jewelry near mov-
ing parts such as PTO shafts, fans, belts and pul-
leys.
• Keep hands away from moving parts.
• Make sure there is ample fresh air when operat-
ing the engine in a confined area.
• Keep guards in place over fans, belts, pulleys,
etc.
e-floorcare
iii
Page 6
iv
Page 7
1. General Information
Introduction
This manual deals with specific mechanical and
electrical information needed by engine mechanics
for troubleshooting, servicing, repairing, or over-
hauling the engine.
The Parts Manual contains detailed exploded views
of each assembly and their individual piece part
numbers and names for ordering replacement
parts.
Features of the Performer OHV220 engine are:
• Overhead valve arrangement enables high
power and low fuel and oil consumption
• V-twin, four stoke design
• Air-cooled and gasoline fueled
• The light-weight and compact design make it
easy to install and utilize for many applications.
• A steel crankshaft and high-load bearing offer
durability.
• Pressure lubrication system and large capac-
ity air cleaner enhance reliability of the engine.
• The combustion chamber shape, along with
a tuned exhaust valve system, enhances the
low exhaust emission and provides high
torque at low speed.
A steel crankshaft and high-load bearing offer dura-
bility. The pressure lubrication system and large ca-
pacity air cleaner enhance reliability of the engine.
The illustrations and procedures presented in each
section apply to the Performer OHV220 Engine.
The blower housing side of the engine is the front
end. Right and left sides are determined by viewing
the engine from the front. The No. 1 cylinder is on
the right; the No. 2 cylinder is on the left (Figure 1-1).
Spark Plug
Oil Filter
Oil Drain
Valve
Carrier
Oil Fill Cap
Dip Stick
Air Cleaner
Cover
Spark Plug
Voltage
Regulator
Blower
Housing
FRONT VIEW REAR VIEW
Starter
Motor & Solenoid
Speed Control
Solenoid (Optional)
Carrier
PTO Shaft
FIGURE 1-1. PERFORMER OHV220 ENGINE
1-1
Page 8
If a major repair or an overhaul is necessary, a
trained, experienced mechanic should either do the
job or supervise and check the work of the mechan-
ic assigned to the job to ensure that all dimensions,
clearances, and torque values are within the specified tolerances.
TABLE 1-1. ENGINE MODEL NUMBER
P 220 GI OHV XXX A
| |||||
1 23456
About this Manual
Use the table of contents for a quick reference to the
separate engine system sections.
Section 2 contains the specifications for the
OHV220 engine for fluids, torques, clearances and
tolerances.
The troubleshooting guide in Section 3 provides a
quick reference for locating and correcting engine
troubles.
Section 4 describes various engine system operations and contains electrical diagrams for the:
• Engine Wiring
• Charging System
• Starter System.
Section 5 describes the engine disassembly proce-
dure when performing a major overhaul. The proce-
dure provides step-by-step instructions for removal
and disassembly of engine components.
Section 6 describes inspection and assembly in-
structions for engine components.
MODEL NUMBER
Use only Genuine Onan " replacement parts to for
quality and the best possible repair and overhaul re-
sults.
1. Model Letter – Performer
2.Number of Cylinders and Rated Horse Power
A.“220” designates 2 Cylinders at 20 HP
3.Engine Fuel Type and Engine Type – Gas Industrial
4. Engine Type – Overhead Valves
5. Engine Specific Model Number
6.Model Nomenclature Revsion
HOW TO OBTAIN SERVICE
When the Performer 220OHV requires service,
contact the nearest dealer or distributor. Factory-
trained Parts and Service representatives are ready
to handle your service needs.
If you are unable to locate a dealer or distributor,
consult the Yellow Pages. Typically, our distributors
are listed under:
GENERATORS-ELECTRIC or
ELECTRICAL PRODUCTS
For the name of your local Cummins/Onanor
Onan-only distributor in the United States or Can-
ada, call 1-800-888-ONAN (this automated service
utilizes touch-tone phones only). By entering your
area code and the first three digits of your local tele-
phone number, you will receive the name and tele-
phone number of the distributor nearest you.
For outside North America, call Onan Corporation,
1-612-574-5000, 7:30 AM to 4:00 PM, Central
Standard Time, Monday through Friday. Or, send a
fax to Onan using the fax number 1-612-574-8087.
WARNING
ment can result in severe personal injury, death,
and/or equipment damage. Service personnel
must be qualified to perform electrical and/or
mechanical service.
Incorrect service or parts replace-
Whenever contacting an dealer or distributor for in-
formation, parts or service, always provide the model number and the serial number marked on the
nameplate of the engine.
See Ta ble 1-1 for an explaination of the engine
model number.
PERFORMANCE CURVE
The power curve shown in Figure 1-2 conforms to
SAE internal combustion engine standard test code
J1349.
The continuous rated output is the output of an en-
gine at optimum governed speed which is prefera-
1-2
Page 9
ble for engine life and fuel consumption. When the
engine is installed, the rated output should be lower
than shown.
The maximum torque is the torque rated on the out-
put shaft while the engine is running at maximum
output per revolution.
N–m
(
kgf–m)
45(4.59
)
15
(
20.1
kW
(HP)
10
(
13.4
HORSEPOWER
35(3.57
MAXIMUM TORQUE
MAXIMUM HORSEPOWER
)
)
)
TORQUE
CONTINUOUS
RATED HP
5
(
)
6.7
2000 2400 2800 3200 3600
REVOLUTION r.p.m
FIGURE 1-2. OHV220 PERFORMANCE CURVE
1-3
RECOMMENDED
HORSEPOWER RANGE
Page 10
1-4
Page 11
2.Specifications
PERFORMER OHV220 ENGINE SPECIFICATIONS
This Manual contains SI metric equivalents that follow immediately in parentheses
after the U.S. customary units of measure.
Engine Type 4-Cycle, V-Twin Cylinder, Horizontal Shaft, Overhead Valve,
Rated Output 20.5 HP/3600 rpm (15.3 kW/3600)
Continuous Output 16.0 HP/3600 rpm (11.9kW/3600)
Bore x Stroke 3.15” x 2.56” (80 mm x 65 mm)
Displacement 39.90 cu in (653 cc)
Compression Ratio 8.3:1
Maximum Output 15.3 kW / 20.5 HP / 3,600 rpm
Maximum Torque 32.7 ft/lbs @ 2,200 rpm
Starting System Electric Start
Carburetor Horizontal Shaft, Float Type
Fuel Unleaded Gasoline using a Diaphragm Pulse Pump
Lubrication Full Pressure with Full Flow Spin-On Filter
Oil Type Automobile Engine Oil SAE Class SE or Higher (See Engine Oil Recom-
mendation)
Oil Capacity 1.64 qt (1550 cc)
Charging System 12 volt 15 amp
Dry Weight 96.9 lbs (44 kg)
Dimensions (LxWxHx) 12.5” x 19.0” x 19.0” (317 mm x 477 mm 475 mm)
Direction of Rotation CCW as Viewed from the PT shaft side
Cooling System Forced Air Cooling
Ignition System Flywheel Magneto (Solid State)
Spark Plug Type NGK–BP6ES or BRP6ES (Champion – N9YC or RN9YC)
Gap: 0.023–0.027 in (.0.6–0.7 mm)
Governor System Centrifugal Fly Weight
Air Cleaner Double Element Assembly
2-1
Page 12
DIMENSIONS AND CLEARANCES
ÇÇÇ
ÇÇÇ
ÇÇÇ
ÇÇÇ
ÇÇÇ
ÇÇÇ
ÇÇÇ
Cylinder Head
Flatness
Valve seat contact
width
Valve guide inside
diameter
ITEM
Intake/
Exhaust
STANDARD
inches (mm)
0.002 or less
(0.05 or less)
0.028 – 0.039
(0.7 – 1.0)
0.2376 – 0.2383
(6.035 – 6.053)
MAXIMUM
inches (mm)
0.004 (0.1)
0.079 (2.0)
0.242 (6.15)
Cylinder
Inside diameter
Rebore when the
difference between
the max. and min. of
diameter reaches
STD
3.1496 – 3.1504
(80.000 – 80.019
0.004 (0.1)
1st
Reboring
2nd
Reboring
Roundness after reboring
3.159 – 3.160
(80.250 – 80.269)
3.169 – 3.170
(80.500 – 80.519)
3.159 – 3.160
(80.250 – 80.269)
––––––––
0.004 (0.01) ––––––––
Cylindricity after reboring 0.0006 (0.015) ––––––––
2-2
Page 13
Piston
16 mm
ITEM
STD
STANDARD
inches (mm)
3.148 – 3.149
(79.968 – 79.988)
MAXIMUM
inches (mm)
3.145 (79.878)
Piston size (at skirt
in thrust direction)
Ring groove side
clearance
Piston pin hole
1st outer
diameter
2nd
outer
diameter
Top
2nd
Oil Ring
3.158 – 3.159
(80.218 – 80.238)
3.168 – 3.169
(80.468 – 80.488)
0.0002 – 0.0035
(0.05 – 0.09)
0.0012 – 0.0028
(0.03 – 0.07)
0.0022 – 0.0069
(0.057 – 0.175)
0.8262 – 0.8269
(20.989 – 21.002)
3.155 (80.128)
3.164 (80.378)
0.006 (0.15)
0.006 (0.15)
0.006 (0.15)
0.8281 (21.035)
Piston pin outer di-
ameter
Clearance between
piston and cylinder
at skirt area
0.8264 – 0.8268
(20.991 – 21.000)
0.0005 – 0.0020
(0.012 – 0.051)
0.8251 (20.960)
0.0098 (0.25)
2-3
Page 14
ITEM
Piston (continued)
STANDARD
inches (mm)
MAXIMUM
inches (mm)
Piston ring end gap
Connecting Rod
Large end inner
diameter
Clearance between
crankpin and inner
diameter
&'%#
Top
2nd
Oil
Ring
0.0079 – 0.0157
(0.2 – 0.4)
0.0079 – 0.0276
(0.2 – 0.7)
1.5354 – 1.5361
(39.000 – 39.016)
0.0012 – 0.0024
(0.030 – 0.060)
0.0591 (1.5)
0.0591 (1.5)
1.5394 (39.100)
0.0079 (0.2)
Small end inner
diameter
Clearance between
piston pin and inner
diameter
Large end side
clearance
0.8272 – 0.8277
(21.010 – 21.023)
0.0004 – 0.0013
(0.010 – 0.032)
0.0039 – 0.0157
(0.1 – 0.4)
0.8299 (21.080)
0.0047 (0.12)
0.0394 (1.0)
2-4
Page 15
Crankshaft
ITEM
STANDARD
inches (mm)
MAXIMUM
inches (mm)
Crankpin outer
diameter
Journal diameter
Camshaft
Cam height (internal
and external)
Journal outer
diameter “D”
1.5337 – 1.5343
(38.956 – 38.970)
D1:
1.77102 – 1.77165
(44.984 – 45.000)
D2:
1.77110 – 1.77154
(44.986 – 44.997)
1.4213 – 1.4291
(36.1 – 36.3)
DD
0.7861 – 0.7866
(19.967 – 19.980)
1.5315 (38.90)
–––––––
1.4154 (35.95)
0.7854 (19.950)
Valve
Valve stem outer
diameter
Clearance between
valve stem and
valve stem guide
Intake
Exhaust
Intake
Exhaust
2-5
0.2350 – 0.2356
(5.970 – 5.985)
0.2346 – 0.2352
(5.960 – 5.975)
0.0022 – 0.0033
(0.050 – 0.083)
0.0024 – 0.0037
(0.060 – 0.093)
0.2303 (5.85)
0.2303 (5.85)
0.0118 (0.30)
0.0118 (0.30)
Page 16
Valve (continued)
Ç
Ç
Ç
Valve clearance
Valve spring
ITEM
Intake/
Exhaust
Measured
Cold
STANDARD
inches (mm)
0.0034 – 0.0045
(0.085 – 0.115)
MAXIMUM
inches (mm)
Free length
Tappet
Outer stem diameter
Inner guide diameter
Tappet guide
clearance
1.5551
(39.5)
0.03528 – 0.3533
(8.960 – 8.975)
0.3543 – 0.3549
(9.00 – 9.015)
0.0010 – 0.0022
0.025 – 0.055)
–––––––
0.3516 (8.93)
0.3575 (9.08)
0.0059 (0.15)
Valve seat angle
Cut angle (a)
Contact width (b)
a: 45#
b: 0.028 – 0.039
0.079 (2.0)
(0.7 – 1.0)
a
2-6
Page 17
Rocker Arm
ITEM
STANDARD
inches (mm)
MAXIMUM
inches (mm)
Shaft diameter
Rocker arm hole
diameter
Arm shaft clearance
0.4719 – 0.4722
(11.986 – 11.994)
0.4727 – 0.4734
(12.006 – 12.024)
0.0005 – 0.0015
(0.012 – 0.038)
0.4693 (11.92)
0.4752 (12.07)
0.0059 (0.15)
2-7
Page 18
ELECTRICAL SPECIFICATIONS
COMPONENT
Voltage Regulator
Output
Ignition Coil Resistance
Primary
Secondary
Charge Coil
Nominal Output
Resistance
Ignition coil air gap 0.012 – 0.020”
Fuel Pump
At low idle
At high idle
(minimum measurements)
RATING
12V 15 Amp
7.8 Ohms
7.8 Ohms
12V 15 Amp
9 ohms
(0.3 – 0.5 mm)
Inlet vacuum
2.6” of mercury
Outlet pressure
1.7 psi
Inlet vacuum
2.6” of mercury
Outlet pressure
1.7 psi
ASSEMBLY SPECIFICATIONS
After the first 20 hours of operation the initial oil and
oil filter should be replaced.
CAUTION
some state and federal agencies as causing cancer
or reproductive toxicity. Do not ingest, inhale, or
contact used oil or its vapors.
Used engine oil has been identified by
Thereafter, change the oil every 100 hours of operation and change the oil filter every 200 hours.
TORQUE SPECIFICATIONS
ITEM
Breather cover 26.4 – 43.2 in/lb
Carburetor bolts 12.3 – 13.7 ft/lbs
Charge coil 13.2 – 30 in/lbs
Connecting rod bolts 16.3 – 19.9 ft/lbs
Cylinder head bolts 24.6 – 30.4 ft/lbs
Flywheel nut 61.5 – 68.7 ft/lbs
TORQUE
(2.9 – 4.9 N " m)
(16.7 – 18.6 N " m)
(1.5 – 3.4 N " m)
(22.1 – 27.0 N " m)
(33.3 – 41.2 N " m)
(83.3 – 93.1 N " m)
COMPONENT
End play between
crankshaft and camshaft
CLEARANCE
0.006 – 0.013”
(0.152 – 0.330mm)
Clearance between crank-
case and bearing cover
Clearance between rocker
arm and valve stem end
Clearance between
ignition coils and flywheel
0.003 – 0.004”
(0.085 – 0.115mm)
0.012 – 0.020”
(0.3 – 0.5mm)
ENGINE OIL RECOMMENDATION
EXPECTED AMBIENT
TEMPERATURES
32° F (0 ° C) and higher 30
10 ° F to 100° F (–12 ° C to 38 ° C)
0 ° F to 80 ° F (–18° C to 27° C)
0.014”
(0.36mm)
SAE
VISCOSITY
GRADE
15W-40
(OnaMax)
10W-30
10W-40
Ignition coil 5.1 – 6.6 ft/lbs
(6.9 – 8.8 N " m)
Intake manifold nuts &
Main bearing cover bolts
12.3 – 13.7 ft/lbs
(16.7 – 18.6 N " m)
Oil filter 9 ft/lbs (12.3 N " m)
Oil pressure switch 4.3 – 7.2 ft/lbs
(5.9 – 9.8 N " m)
Oil relief plug 10.9 – 18.1 ft/lbs
(11.8 – 14.7 N " m)
Rocker arm nut 7.2 – 10.1 ft/lbs
(9.8 – 13.7 N " m)
Rocker arm cover 26.4 – 43.2 in/lbs
(2.9 – 4.9 N " m)
Spark plug: new
8.7 – 10.9 ft/lbs
11.8 – 14.7 N " m)
Used
16.6 – 19.5 ft/lbs
(22.5 – 26.5 N " m)
Starter motor bolts 12.3 – 13.7 ft/lbs
(16.7 – 18.6 N " m)
–20° F to 50 ° F (–28 ° C to 10 ° C) 5W-30
2-8
Page 19
3.Engine Troubleshooting
Starter does not
operate
Starter operates but
Starter operates but
engine does not start
while cranking
WARNING
present hazards that can result in severe per-
sonal injury or death. Only qualified service per-
sonnel with knowledge of fuels, electricity, and
machinery hazards should perform service pro-
cedures. Review the safety precautions on the
inside cover page.
Many troubleshooting procedures
Problem
Poor connection of key or starter
switch wiring
Discontinuity between key switch or
start switch and starter motor
Discontinuity between battery and
starter motor
Weak or low charged battery Charge or replace battery
Possible Cause Remedy
WARNING
burns. Always allow the engine time to cool
before performing any maintenance or service.
Refer to other sections within this manual or the Op-
erators Manual for procedures to test, adjust, repair
or replace engine components.
Hot engine parts can cause severe
Check, repair or replace
Replace wiring
Replace battery cables
Low engine speed
while cranking
Poor battery terminal connections Check and clean terminals, replace if
damaged
Faulty solenoid switch Check, repair or replace
Faulty starter motor Repair or replace starter
Crankshaft has seized Check crankshaft bearings and crank-
shaft bearing surface
A piston and cylinder have seized Check pistons and cylinder bores
No fuel in system Refill
Poor connection or discontinuity of
ignition system wires
Faulty starter motor Slow cranking RPM caused by a
Low battery Charge battery
Bad connection between battery and
starter motor
Bad connection between battery and
ground
Starter motor has worn brushes or
bearing
Improper engine oil Replace with recommended engine oil
Check wire connections and ignition
coils for shorts
faulty starter motor or low battery volt-
age at starter
Clean or repair
Clean or repair
Repair or replace starter motor
3-1
Page 20
Problem
Low compression/
Insufficient output
Possible Cause Remedy
Spark plug:
Improper gap
No insulator
Carbon deposits
Adjust
Replace
Clean
Ignition system
malfunctions
Fuel system malfunc-
tions
Ignition coil
No insulation or discontinuity
Bad connection or discontinuity of
Check for grounded wire and replace
Replace coil(s)
ignition coil
Improper air gap between ignition coil
Check and adjust
and flywheel
Fuel tank is empty Refill tank
Fuel pump is plugged up Disassemble and clean
Fuel hose is plugged or pinched Check lines, replace if necessary
Air is mixing into fuel lines Check and tighten connections
Plugged fuel filter or air infiltration Clean or replace fuel filter
Carburetor
Flooding
Clogged or damaged
Throttle valve not functioning
The floats are sticking
Disassemble and clean
Check throttle shaft and linkage,
adjust governor lever
Low fuel flow to carburetor
Faulty fuel cut-off valve or wiring
Engine idles too high Adjust or replace control solenoid
Idle unstable Check govenor linkage and springs
Loose spark plug(s) Retighten or replace plug wire
Head gaskets are leaking Retighten or replace gasket
Worn piston ring(s) or seizure Replace ring(s)
Incorrect valve and seat contact Adjust or replace
Valve stem seizure Repair or replace
Incorrect valve clearance Check and adjust
Ignition coil(s) faulty Check and replace
Improper gap between coil and fly-
Check and adjust
wheel
Charge coil is demagnetized Replace charge coil
Fuel system problems Check system
Low air intake Clean air cleaner elements
Check throttle valve for full opening
3-2
Page 21
Problem
Pre-Ignition
Possible Cause Remedy
Cooling air flow obstructed Check air inlet and cylinder baffle and
clean out
Improper engine oil Replace
Overheating
High oil consumption
Lean air/fuel mixture Check for plugged passages in carbu-
retor
Excessive back pressure of exhaust
system
Check, clean or replace muffler and
spark arrestor (if equipped)
Engine is overloaded Change to rated load
Oil is leaking
Loose drain valve or gasket
Filter not properly installed
Bearing cover bolts are loose
Check and replace gaskets if neces-
sary
Bearing cover gasket is worn or
damaged
Oil is diluted
Piston oil rings are faulty
Piston rings worn, siezed or making
poor contact
Replace piston rings
Hone cylinders and install oversize
piston rings
Piston and cylinder are worn
Valve stem is worn
Oil level is too high
Cylinder breather is faulty
Replace valve guides
Adjust oil level
Replace breather cover assembly
Ignition sytem faulty
Ignition system wiring is poor
Improper or damaged spark plug(s)
Fuel system malfunction
Lean air/fuel mixture
Carburetor damaged
Fuel lines clogged or damaged
Vacuum leak
Cylinder head
Carbon deposit in combustion
chamber
Cylinder head gasket leaking
Valve system
Improper valve clearance
Valve heat deterioration
Valve spring deterioration
3-3
Check wiring and connections
Clean or replace
Check for plugged carburetor
Disassemble and clean
Clean or replace
Replace gaskets
Remove and clean out carbon
Replace gasket
Adjust valve lash
Replace or regrind
Replace springs
Page 22
Problem
Engine misfire
Possible Cause Remedy
Ignition system
Improper spark plug gap or dam-
aged plug
Faulty ignition coil
Damaged or poor connection of
ignition wires
Fuel system
Lean air/fuel mixture due to clogged
carburetor
Improper gasoline or water
infiltration
Engine valves
Valves are deteriorated or out of
adjustment
Valve spring is faulty
Clean, adjust or replace
Replace coil(s)
Check connections or replace wires
Disassemble and clean carburetor
Replace gasoline and filter
Adjust or replace valves
Replace springs
3-4
Page 23
4. Engine Systems
INTRODUCTION
This section presents an overview of the following
OHV220 engine systems.
• Lubrication System
• Fuel System
• Electrical System
• Starting System
LUBRICATION SYSTEM
Oil and Filter Change
Refer to Periodic Maintenance in the Operator’s
Manual for oil and filter change intervals and proce-
dures.
Pressure Lubrication
All engines use an oil pump to provide a constant
flow of oil to the engine parts. The oil supply collects
in the bottom of the crankcase. A relief valve is used
to control oil pressure.
Oil Pump Operation
A large trochoid type oil pump is driven directly by
the crankshaft, delivering pressurized oil to the jour-
nal and pin portions of crankshaft, camshaft etc.
A cartridge type oil filter is located in the bottom of
the crankcase. Through this cartridge oil filter, oil is
forced onto rotating parts such as journal and pins
of the crankshaft and camshaft.
Oil is fed through the oil pump filter into the oil pump.
The oil pressure is adjusted by the relief valve after
discharging from oil pump. Oil is then splashed onto
the cylinder, piston, and the cylinder head valve
system. See Figure 4-1.
A by-pass valve is incorporated into the cartridge
type oil filter. In the event the oil filter element be-
comes clogged, the engine oil is fed through the by-
pass valve into the crankcase oil passage.
RELIEF VALVE
OIL FILTER
CAMSHAFT
CRANKSHAFT
OIL PUMP
OIL PUMP FILTER
FIGURE 4-1. LUBRICATION SYSTEM
4-1
Page 24
Relief Valve
The relief valve is located on the bottom of the
crankcase. It is non-adjustable and normally does
not require maintenance. However, each part of the
relief valve is replaceable.
Oil Pressure Switch
The oil pressure switch is mounted on the same
housing as the oil filter. If oil pressure becomes low
while flowing to the oil pump, the switch will trigger a
shutdown condition.
Crankcase Breather
WARNING
Ignition of fuel can result in se-
vere personal injury or death. Thoroughly
clean up any spilled fuel. Do not smoke or
allow any flame, spark, pilot light, or arcing
switch or equipment, or other source of
ignition near the work area or areas sharing
ventilation.
1. Operate the engine at an idle for five minutes
until the carburetor is full of fuel.
2.Shut the engine off and remove the fuel supply-
line from the fuel pump.
3.Connect a vacuum gauge to the fuel pump inlet
using a piece of fuel hose with clamps.
The crankcase breather prevents pressure from
building up in the crankcase. It also prevents oil
contamination by removing moisture or gasoline
vapors and other harmful blow-by materials from
the crankcase. These vapors are routed to the car-
buretor where they are mixed with incoming air and
burned in the combustion chamber.
A sticky breather valve can cause oil leaks, high oil
consumption, rough idle, reduced engine power,
and a rapid formation of sludge and varnish within
the engine.
Replace the breather if it’s broken or cracked, or if
the crankcase becomes pressurized indicated by
oil leaks at the seals or excessive oil in the air clean-
er housing.
FUEL SYSTEM
The fuel system consists of a fuel pump, carburetor,
fuel filter, shut-off valve and control linkage.
4. Start the engine and allow to idle for at least five
seconds. Record the vacuum gauge reading.
5. Move the throttle control to the high idle posi-
tion. Wait at least five seconds and record the
vacuum gauge reading.
6.Shut the engine off and remove the vacuum
gauge hose from the fuel pump inlet. Connect
the fuel inlet line to the fuel pump.
7.Shut the engine off and remove the pressure
gauge hose from the fuel pump outlet. Connect
the fuel outlet line to the fuel pump.
WARNING
lines have been identified by some state and
federal agencies as causing cancer or
reproductive toxicity. Do not to ingest, inhale or
contact gasoline or its vapors.
Benzene and lead in some gaso-
8. Remove the fuel outlet line from the fuel pump.
9. Connect a pressure gauge to the fuel pump
outlet using a piece of fuel hose with clamps.
Fuel Pump
A diaphragm type fuel pump is mounted on the front
of the engine. The pump is operated by vacuum
pressure inside the crankcase.
The fuel pump is not serviceable and should be re-
placed if faulty.
Fuel Pump Test Procedure
Before testing, make certain the fuel pump vacuum
and fuel line connections are tight and free of leaks.
10.Start the engine and allow to idle for at least five
seconds. While holding the pressure gauge
level with the pump outlet, record pressure
gauge reading.
11.Move the throttle control to the high idle posi-
tion and allow the engine to run for at least five
seconds. While holding the pressure gauge
level with the pump outlet, record pressure
gauge reading.
12.Shut the engine off and remove the pressure
gauge hose from the fuel pump outlet. Connect
the fuel outlet line to the fuel pump.
4-2
Page 25
Replace the fuel pump if test readings are not within
values specified in Table 4-1.
TABLE 4-1. PULSE PUMP TEST SPECIFICATIONS
keeping the fuel at a predetermined level. Fuel va-
pors are sucked into the combustion chamber
through air vents in the carburetor body. See Figure
4-2.
ENGINE
SPEED
Low Idle 2.6 inches
PUMP INLET
VACUUM
(Minimum)
PUMP OUTLET
PRESSURE
(Minimum)
1.7 psi
of mercury
High Idle 2.6 inches
1.7 psi
of mercury
CARBURETOR
The engine is equipped with a down draft carburetor
with a float-controlled fuel system and fixed main
jet.
Carburetors are calibrated carefully for sure starts,
good acceleration, low fuel consumption and suffi-
cient output.
FLOAT SYSTEM Fuel flows from the fuel tank into
the float chamber through a needle valve. When the
fuel rises to a specific level, the float rises. When its
buoyancy and fuel pressure are balanced, the
needle valve closes to shut off the fuel, thereby
PILOT SYSTEM The pilot system feeds the fuel to
the engine during idle and low-speed operation.
Fuel is fed through the main jet to the pilot jet, where
it is metered and mixed with the air from the pilot air
jet. The fuel/air mixture is fed to the engine through
the pilot outlet and the by-pass. When idling, the
fuel is fed mainly from the pilot outlet.
MAIN SYSTEM The main system feeds the fuel to
the engine during medium- and high-speed opera-
tion. Fuel is metered by the main jet and fed to the
main nozzle. Air metered by the main air jet is mixed
with the fuel through the emulsion tube, and the
mixture is atomized out of the main bore. Then it’s
mixed again with the air taken through the air clean-
er into an optimum fuel-air mixture, which is sup-
plied to the engine.
CHOKE The choke is used for easy start-up when
the engine is cold. When the starter is operated with
a choke valve fully closed, the negative pressure
applied to the main nozzle increases and draws
more fuel; thus easily starting the engine.
NEEDLE VALVE
FUEL
FUEL INLET
PIPE
CHOKE VALVE
AIR VENT HOLE
FLOAT
MAIN NOZZLE
THROTTLE
VALVE
BY–PASS
AIR
PILOT AIR JET
MAIN AIR JET
TAMPER CAP
MIXTURE
PILOT OUTLET
FIGURE 4-2. CARBURETOR SYSTEM
EMULSION TUBE
SHUT-OFF
VALVE
MAIN JET
PILOT JET
4-3
Page 26
SHUT-OFF VALVE A fuel shut-off valve prevents
engine run-on when the engine is turned off. When
the engine is on, the valve is activated and the
plunger is pulled in to open the main jet. When the
engine is off, the power source to the valve is off.
The plunger is pushed out by the return spring and
stops the fuel flow to the main jet.
Carburetor Replacement
CHARGING SYSTEM
Magneto
The ignition system contains a flywheel magneto
with automatic advancing characteristics. This sys-
tem is free from start-up failure due to dirty, burnt or
a corroded point surfaces because there are no
points.
Do not adjust the fuel mixture, rebuild or overhaul
the carburetor. A malfunctioning carburetor should
be replaced. Before replacing a carburetor, however, make certain that:
• All other necessary engine and generator ad-
justments and repairs have been performed
• The carburetor is actually malfunctioning
(see Section 3: Engine Troubleshooting).
CAUTION
Unauthorized modifications or re-
placement of fuel, exhaust, air intake, or speed
control system components that affect emission on California certified engines are prohibited by law in the State of California.
To remove the carburetor, remove the air cleaner,
disconnect the fuel line, choke, and throttle link-
ages, and unbolt the carburetor from the intake
manifold. When reinstalling the carburetor, always
use a new gasket. Readjust the choke and throttle
cables and engine speed as instructed in the Oper-
ator’s Manual.
Speed Control Solenoid (Optional)
The speed control solenoid monitors the rate of the
load and automatically adjusts the engine to the ap-
propriate idle speed.
The solenoid is faulty if the idle does not pull to low.
Replace the solenoid.
The electronic automatic advancing provides easy
starts and stable high performance at operating
speed by advancing the ignition timing to the most
suitable point.
THEORY: Refer to Figure 4-3. Revolution of the fly-
wheel generates electricity on the primary side of
the ignition coil, and the base current )# to the pow-
er transistor. Current )# turns the power transistor
“on” and the electric current )$ flows.
During low idle, after the flywheel reaches the igni-
tion point, the low speed ignition timing control circuit runs the base current )% turning the signal tran-
sistor A “on”. This allows the current )# to bypass as
current )&. The power transistor turns “off” and the
current )$ is abruptly shut, resulting in high voltage
generated in the secondary coil producing sparks at
the spark plugs.
During high speed operation, the advancing control
circuit operates the ignition timing to run base cur-
rent )' turning the signal transistor B “on”. This al-
lows current )# to bypass as current )(. The power
transistor turns “off” and the current )$ is abruptly
closed, resulting in high voltage generated in the
secondary coil producing sparks at the spark plugs.
The engine timing advances relative to the engine
speed controlled by this circuit. This timing advance system is contained within the magneto coils
and is not serviceable nor can the individual electronic components be replaced.
4-4
Page 27
Resistor
I 1
Low Speed
Ignition
Timing
Control Circuit
ELECTRONIC ADVANCING FLYWHEEL
I 3
MAGNETO SYSTEM
Power Transistor
Primary Coil
Automatic
Advancing
Control
Signal Transistor A
Circuit
I 4
(
B.T.D.C.
IGNITION TIMING
I 5
I 2
Signal Transistor B
I 6
)
STEP ADVANCING
500 1000 2000 3000 (r.p.m.)
ENGINE REVOLUTION
Secondary Coil
Spark Plug
FIGURE 4-3. MAGNETO SYSTEM
Ignition TIming
The ignition timing is preset at the factory and is not
adjustable.
Spark Plugs
Check or replace spark plugs as recommended in
the Periodic Maintenance Schedule in the Opera-
tor’s Manual. Replace spark plugs that show signs
of fouling or electrode erosion.
Battery Inspection
WARNING
ty glasses and do not smoke while servicing
batteries. Lead acid batteries give off a highly
explosive hydrogen gas which can be ignited by
flame, electrical arcing or smoking.
Battery gas is explosive. Wear safe-
Check battery cells with a hydrometer. The 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 ac-
celerate discharge and battery failure.
Keep the battery terminals clean and tight. Push the
cable terminal down flush with or slightly below the
top of the battery post. After making connections,
coat the terminals with a light application of petro-
leum jelly or grease to retard corrosion.
WARNING
Always disconnect the negative
cable first, and reconnect it last to reduce the
risk of arcing and explosion.
4-5
Page 28
Jump Starting
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 help prevent starter
damage, battery damage, and personal injuries.
4. Attach one end of the negative booster cable
(black) to the negative (–) terminal of the boost-
er battery. Attach the other end of the negative
cable to a solid chassis ground on your engine.
5. Jump starting in any other manner may result
in damage to the battery or the electrical sys-
tem.
1. Disconnect engine load.
2.Use a battery of the same voltage (12V) as is
used with your engine.
3.Attach one end of the positive booster cable
(red) to the positive (+) terminal of the booster
battery. Attach the other end on the positive
cable to the positive (+) terminal of your engine
battery.
WARNING
Electrical arcing can cause se-
vere personal injury. Do not allow positive
and negative cable ends to touch.
WARNING
Jump starting a battery incor-
rectly can cause either battery to explode,
resulting in severe personal injury or death.
Do not allow any spark, flame, pilot light, lit
cigarette, or other ignition sources near the
battery. Do not jump start a frozen battery.
6.Turn ignition switch to start engine.
CAUTION
Overcranking the engine can
cause starter damage. Do not engage start-
er for longer than 30 seconds. If engine
does not start, allow 5 minutes for starter to
cool between cranking intervals.
4-6
Page 29
STARTING SYSTEM
Starter Service
Starter
Normally, the starter requires little or no service oth-
er than possible brush replacement. However, if
through accident or misuse, the starter requires ser-
vice or overhaul, the following provides the informa-
tion necessary to perform this service.
Functional Operation
When the engine is turned ON, low electric current
(M # ) flows through the coil of the solenoid and the
coil is excited. The plunger is pulled and higher current (S # ) flows through the starter. See Fig 4-4
When starting the engine, note the starter motor ac-
tion. The pinion gear should mesh quickly with the
flywheel ring gear and spin the engine. Once the en-
gine starts and the solenoid opens, the starter
should disengage and stop. If the starter cranks the
engine slowly, or not at all, check the start circuit
components. Failure to crank is usually caused by a
low battery charge, defective battery cables, cor-
roded or poor connections, or low temperatures. Af-
ter checking these variables and the starter contin-
ues to crank slowly, remove and repair the starter.
Assembly: Assembly is the reverse of disassem-
bly. Apply grease to the shift fork hinge and prongs
and the splines on the armature shaft. Torque
mounting bolts as specified in Section 2, page 2-8.
STARTER MOUNTED
SOLENOID
FIGURE 4-4. STARTING SYSTEM DIAGRAM
CUSTOMER CONNECTION
4-7
Page 30
THROUGH
BOLT
REAR
COVER
BRUSH &
BRUSH
SPRING
SOLENOID
DUST
COVERS
SHIFT LEVER
ARMATURE
DUST
COVER
CHARGE
COIL
PINION
STOPPER
PINION
ASSY.
DUST
COVER
BRUSH
HOLDER
THRUST WASHERS
BRUSH
SET
FIGURE 4-5. STARTER ASSEMBLY
Solenoid Inspection
For typical wiring connections at the starter sole-
noid, refer to Figure 4-6.
Before removing a starter because the engine does
not crank:
1. Make sure the battery is fully charged, the con-
nections are clean and tight and the battery
cables are in good condition. If it is necessary
to reconnect the battery, connect the positive
( + ) battery cable first.
FRAME
2.Disconnect the spark plug cable so that the engine will not start. Bypass the start circuit with
a jumper between the start and the positive battery ( + ) terminal on the solenoid (Figure 4-6). If
the engine cranks, the solenoid and starter are
probably okay. If the engine does not crank, go
to Step 3.
3.Bypass the starter solenoid with a jumper be-
tween the motor and the positive battery ( + ) terminal on the solenoid (Figure 4-6). If the motor
responds, it is probably okay and it may only be
necessary to replace the solenoid.
4-8
Page 31
START
TERMINAL
(B)
BATTERY
POSITIVE ( + )
TERMINAL
(A)
MOTOR
TERMINAL
(C)
FIGURE 4-6. STARTER SOLENOID TERMINALS
Pinion
Inspection/Service: Refer to Figure 4-7. Replace
the pinion assembly if the pinion teeth and armature
shaft splines are worn or damaged. Check the overrunning clutch by rotating the pinion clockwise and
counterclockwise. Replace the pinion assembly if it
does not turn smoothly counterclockwise or lock
clockwise.
CAUTION
clutch in liquid cleaning solution will result in
starter damage.
Cleaning the pinion over-running
1./.0/
WARNING
Accidental starting of the engine
can result in severe personal injury or death.
Disconnect the negative (–) battery cable and
spark plug wire before servicing the engine,
controls, or associated equipment.
)-<%''&
FIGURE 4-7. CHECKING OPERATION OF THE PIN-
ION OVER-RUNNING CLUTCH
4-9
Page 32
CARBURETOR
FUEL
SOLENOID
BLACK
STOP
DIODE
RED
BLACK
RELAY
BLUE
YELLOW
BYPASS
DIODE
WHITE
BLUE
RED
BLACK
OIL
PRESSURE
SWITCH
BLUE
IGNITION
COILS
BLACK
CARBURETOR
BLACK
CHARGE
COIL
FUEL
SOLENOID
BLACK
VOLTAGE
REGULATOR
CUSTOMER
CONNECTION
GREEN
STARTER
MOTOR
YELLOW
BLACK
STARTER
SOLENOID
FIGURE 4-8 ENGINE WIRING DIAGRAM (6 PIN)
RED
WHITE
BLACK
BLACK
STOP
DIODE
RED
BLACK
CUSTOMER
CONNECTION
RED
BATTERY
12V 30 AH
RUN
DIODE
FUSE
RED
RED
RED
GRAY
GREEN
CONTROL
SOLENOID
RED
BYPASS
DIODE
OIL
PRESSUR
E SWITCH
RED
IGNITION
COILS
CHARGE
COIL
BLACK
BLACK
FIGURE 4-9 ENGINE WIRING DIAGRAM (4 PIN)
VOLTAGE
REGULATOR
STARTER
MOTOR
4-10
GREEN
BLACK
YELLOW
YELLOW
CUSTOMER
CONNECTIONS
STARTER
SOLENOID
BATTERY
12V 30 AH
Page 33
5. Disassembly
When complete engine disassembly is necessary,
first remove all complete assemblies. Individual as-
semblies such as the fuel pump, starter and the carburetor can be disassembled and repaired at anoth-
er time.
Suggestions
• If you are uncertain about linkages, wiring or
hose connections, label or tag items before
removing them.
• Have small boxes on hand to hold disas-
sembled parts by group.
• Prevent loosing and misplacing parts by tem-
porarily assembling each group of disassembled parts.
• Clean parts in washing fluid if necessary.
WARNING
and can cause severe personal injury or
death if used improperly. Follow the manufacturer’s recommendations when clean-
ing parts.
Most solvents are flammable
Preparation
1. Remove the fuel supply line.
CAUTION
olines have been identified by some state
and federal agencies as causing cancer or
reproductive toxicity. Do not to ingest, in-
hale or contact gasoline or its vapors.
2.Disconnect exhaust and battery cables, negative (–) cable first.
WARNING
drogen gas given off by batteries, causing
severe personal injury. Arcing can occur if
the negative (–) battery cable is connected
and a tool being used to connect or disconnect the positive (+) battery cable accidentally touches the frame or other grounded
metal part of the set. To prevent arcing, al-
ways remove the negative (–) cable first,
and reconnect it last.
3.Disconnect the electrical connector between
the engine and accessory.
Benzene and lead in some gas-
Arcing can ignite explosive hy-
Special Tools
Both American- and metric-size sockets and
wrenches will be needed. A ring spreader will be
needed to remove and install pistion rings. For pull-
ing the flywheel, a universal-type puller can be used
as shown below.
FIGURE 5-1. FLYWHEEL PULLER
4. Remove the engine from its mountings and
place upright in a well lit and ventilated work
area.
5. Drain the engine oil.
CAUTION
by some state and federal agencies as causing
cancer or reproductive toxicity. Do not ingest,
inhale, or contact used oil or its vapors.
Used engine oil has been identified
Disassembly Procedures
The following pages describe and illustrate engine
disassembly.
5-1
Page 34
Disassembly Procedures
3.Remove the breather tube from the #1 cylinder
head secured with a hose clamp.
1. After the oil has been drained, remove the dip
stick, and dip stick tube.
2.Remove the air cleaner cover, elements and
base secured with (3) 10–32mm cap screws.
WING NUT
STEP 2
10–32 CAP
SCREWS (3 pcs)
OIL FILL TUBE
CLEANER
COVER
AIR
CLEANER
ELEMENT
4. Remove the fuel pump with mount. Disconnect
the fuel hose to carburetor and pulse hose.
5. Remove the blower housing secured with (8)
M6 flange bolts.
STEP 3
BREATHER
PIPE
FUEL HOSE
FUEL PUMP
MOUNTING
BRACKET
STEP 4
PULSE HOSE
OIL LEVEL GAUGE
AND TUBE
STEP 1
CLEANER BASE
FUEL HOSE
BLOWER HOUSING
PULSE HOSE
OIL DRAIN VALVE
STEP 5
M6 FLANGE
BOLT (8 pcs)
FUEL
FILTER
FIGURE 5-2.
5-2
Page 35
6.Remove the speed and choke control linkage
and mounting bracket.
8. Remove the carburetor secured by (2) M8
bolts.
7.Disconnect the wiring harness under the speed
control solenoid. Remove the speed control so-
lenoid and the governor lever, if required.
M8 FLANGE
BOLT : 2 pcs.
STEP 8
CARBURETOR
GASKET, carburetor
M6 NUT (1pc)
GOVERNOR LEVER
M6 BOLT
WASHER (1PC)
NOTE: For reassembly purposes, torque the
carburetor bolts between 12.3 and 13.7 ft/lbs
(16.7 – 18.6 N " m).
CHOKE
CONTROL
ROD
RETURN
SPRING
STEP 6
LINK PIVOT
ROD
SPRING
GOV. ROD
GOVERNOR
SPRING
M6 SELF LOCK
NUT (1 pc)
WAVED
WASHER
CHOKE
CONTROL
LINK
SPEED
CONTROL
LINK
M6 FLANGE
BOLT (3 pcs)
STEP 7
SPEED
CONTROL
SOLENOID
(OPTIONAL)
FLANGE BOLT
(8–32)
SPEED AND CHOKE
LINKAGE MOUNTING
BRACKET
FIGURE 5-3.
5-3
Page 36
9. Disconnect the spark plug wires and the wiring
to each ignition coil. Cut the cable ties securing
wires to the manifold. Remove the coils se-
cured with (2) M6 bolts.
10.Pull out the connector under the relay attached
to the cylinder baffle.
11.Remove the relay, the wire holder, and the two
ground wires secured with flanged bolts.
12.Remove the red/white/blue wire terminal from
the oil pressure switch. Remove the oil pressure switch if necessary. Disconnect the yellow
wire at the starter.
NOTE: For re-assembly purposes, torque the
M6 coil bolts between 5.1 and 6.5 ft/lb (6.9 –
8.8N " m).
STEP 9
SPARK
PLUG CAP
PLUG
TERMINAL
TO STOP DIODE
IGNITION
COIL
M6 BOLT
AND WASHER
(2 pcs.)
M6 BOLT
AND WASHER
(2 pcs.)
IGNITION
COIL
PLUG
TERMINAL
SPARK
PLUG CAP
CYLINDER BAFFLE
CABLE TIES
IGNITION COILS
WIRE
HOLDER
FIGURE 5-4.
5-4
STEP 10, 11 & 12
GROUND TERMINALS
(Not on all models)
ELBOW
OIL
PRESSURE
SWITCH
RELAY and CONNECTOR
(Not on all models)
Page 37
13.Remove all four cylinder baffles secured by M6
bolts.
14.Remove the spark plugs, if necessary.
15.Remove the intake manifold secured by (4) M8
flange nuts.
M8 FLANGE
MANIFOLD GASKET
STEP 13, 14
SPARK PLUG
NUT (2 pcs.)
NOTE: For re-assembly purposes, torque the
M8 manifold nuts between 12.3 to 13.7 ft/lbs
(16.7 – 18.6 N " m).
CYLINDER BAFFLE #3
M6 FLANGE
BOLT (2 pcs.)
INTAKE
MANIFOLD
M6 FLANGE
BOLT (3 pcs.)
CYLINDER BAFFLE #1
M6 FLANGE
BOLT (3 pcs.)
CYLINDER BAFFLE #4
M8 FLANGE
NUT (2 pcs.)
STEP 15
MANIFOLD GASKET
SPARK PLUG
M6 FLANGE
BOLT (3 pcs.)
CYLINDER BAFFLE #2
FIGURE 5-5.
5-5
Page 38
16.Remove the rocker arm covers secured with
(4) M6 bolts each.
17.Before removing the rocker arms and shafts,
turn the flywheel to “dead center” (TDC) with
the mark “T” adjusted to number 1 or 2 in-
scribed on the cylinder head (Figure 6-11). Use
a permanent marker to mark the original posi-
tion of each push rod, rocker arm and valve for
reassembly.
M6 FLANGE
BOLT (4 pcs.)
LIFT HOOK
18.Remove the cylinder head from the engine
body secured with (4) M10 flange bolts each.
NOTE: For reassembly purposes, torque the
cylinder head flange bolts between 24.6 and
30.4 ft/lb (33.3 – 41.2 N " m).
Torque the rocker arm nuts between 7.2 and 10.1
ft/lbs (9.8 – 13.7 N " m).
Torque the rocker arm cover bolts between 26.4
and 43.3 in/lbs (2.9 – 4.9 N " m).
ROCKER ARM
COVER
STEP 16
ADJUSTING
SCREW
M8 NUT (2 pcs.)
ROCKER
SHAFT
ROCKER
ARM
PUSH
ROD
CYLINDER
HEAD 1
GASKET,
rocker arm
M10 FLANGE
BOT (4 pcs.)
GASKET 2
ROCKER
SHAFT
PUSH
ROD
ROCKER
ARM
CYLINDER
HEAD 2
M8 NUT (2 pcs.)
ADJUSTING
SCREW
LIFT HOOK
ROCKER ARM
COVER
STEP 16
M6 FLANGE
BOLT (4 pcs.)
GASKET,
rocker arm
M10 FLANGE
BOLT (4 pcs.)
STEP 18
GASKET 1
STEP 18
FIGURE 5-6.
5-6
Page 39
19.Remove the intake and exhaust valves.
SPRING
RETAINER
VALVE
VALVE
SPRING
WASHER
SPRING
RETAINER
VALVE
SPRING
WASHER
STEP 19
EXHAUST
VALVE
INTAKE
VALVE
GASKET
BREATHER
GASKET, breather
BREATHER
COVER
M6 FLANGE
BOLT (2 pcs.)
COLLET
VALVE
COLLET
STEP 20
OIL SEAL
20.Disassemble the breather assembly secured
to the #1 cylinder head with (2) M6 flange bolts.
Do not reuse the intake valve stem oil seal. Each
time the valves are removed from the cylinder
block, a new seal must be used when the valve is
reinstalled.
NOTE: For reassembly purposes, torque the
breather cover flange bolts between 26.4 and
43.2 in/lb (2.9 – 4.9 N " m).
CAUTION
Removing a valve after installing a
valve stem seal can cause seal damage. Do not
allow valve stem groove to come in contact with
the valve stem seal after installation.
FIGURE 5-7.
5-7
Page 40
CAUTION
Improper flywheel removal can
cause gear case damage. Do not use any tools
to pry against the gear cover when removing the
flywheel.
21. Remove the flywheel with the blower unit at-
tached by:
A.Remove the M18 nut, lock washer and
plain washer from the crankshaft.
B.Using a universal flywheel puller, pull the
flywheel away from the gear ring.
C.Replace the crankshaft washers and nut.
22.Pound out the woodruff key on the crankshaft.
NOTE: For reassembly purposes, torque the crank-
shaft nut between 61.5 and 68.7 ft/lbs (83.3 – 93.1
N " m).
STEP 21
FIGURE 5-8.
STEP 22
FIGURE 5-9.
5-8
Page 41
STEP 23, 24, 25
M5 BOLT AND
WASHER (4 pcs.)
LOCK WASHER
WASHER
CRANKSHAFT
NUT (M18)
CHARGE COIL
TAPE
SHAFT
THREADS
FIGURE 5-10.
23.Remove the gear ring.
24. Remove the charge coil secured by (4) M6
bolts and washers.
NOTE: For reassembly purposes, torque the
charge coil bolts between 13.2 and 30 in/lb (1.5 –
3.4 N " m).
BLOWER
UNIT
FLYWHEEL
RING GEAR
STEP 26
25. To avoid damage to the oil seal, wrap the
threaded portion of the crankshaft with electri-
cal tape.
26.Remove the (10) M8 bolts securing the gear
case cover to the engine body. Tap the cover
gently with a soft-faced hammer to loosen it. Be
careful not to damage the gear cover oil seal.
27.With the gear cover removed, the governor
gear can be removed.
FIGURE 5-11.
5-9
Page 42
GOVERNOR
SLEEEVE
29. Using a marker, identify the position and location of each tappet before removing.
WASHER (2 pcs.)
GOVERNOR
GEAR SHAFT
M8 FLANGE
BOLT (10 pcs.)
GOVERNOR GEAR
THRUST BEARING
STEP 27
GASKET
FIGURE 5-13. STEP 28
TAPPET
STEP 29
STEP 27
MAIN BEARING
COVER
FIGURE 5-12.
28. Line up the timing marks of the camshaft gear
and the crankshaft gear, then pull out the cam-
shaft.
TAPPET
CAMSHAFT
FIGURE 5-14.
5-10
Page 43
30.Remove the ridge from the top of each cylinder
with a ridge reamer before removing the piston.
31. After removal, mark the location of each piston
and rod assembly so they can be returned to
their respective cylinders.
Remove the piston and connecting rod by:
A.removing the (2) M8 connecting rod bolts,
B.take off the connecting rod cap,
C.push the connecting rod upwards and re-
move with piston.
PISTON
RING SET
CLIP
STEP 32
PISTON PIN
CLIP
CLIP
CONNECTING
ROD CAP
NOTE: For purposes of reassembly, torque the
connecting rod bolts between 16.3 and 19.9 ft/lb
(22.1 – 27.0 N " m).
32.Use a piston ring spreader to remove the piston
rings.
33.Remove the m18 nut and washers securing the
crankshaft in position and remove crankshaft.
A.Retain the spacer on the crankshaft.
CLIP
PISTON PIN
PISTON
RING SET
PISTON
CONNECTING ROD
STEP 32
STEP 33
SPACER
STEP 30
CRANKSHAFT
CONNECTING
ROD
CONNECTING
ROD CAP
M8 CONNECTING
ROD BOLT : 2 pcs.
M8 CONNECTING
ROD BOLT : 2 pcs.
M18 NUT
FIGURE 5-15.
5-11
Page 44
34. Remove the remainder of the engine crank-
case parts.
A.Remove the starter and solenoid secured
by (2) M8 flange bolts.
E.Twist off the canister oil filter.
NOTE: For reassembly purposes, torque the
starter mounting bolts between 12.3 and 13.7 ft/
lbs (16.7 – 18.6 N " m).
B.Remove the oil pump assembly secured
by (4) M6 flange bolts.
C.Remove the governor lever shaft secured
with a snap pin and washer.
D.Remove the inner oil pump filter secured
by (1) M10 flange bolt.
STEP 34
M8 FLANGE
BOLT (2 pcs.)
SNAP PIN
WASHER
Torque the oil filter bolt to 9 ft/lbs (12.3 N " m).
Torque the oil relief plug between 10.9 and 18.1
ft/lbs (11.8 – 14.7 N " m).
Refer to the next section Reassembly Procedures
for specific inspection and reassembly instructions.
M6 FLANGE
BOLT (4 pcs.)
OUTER
ROTER
INNER
ROTOR
O RING
OIL PUMP
COVER
OIL SEAL
STARTER
SOLENOID
STARTER
10–32 FLANGE
BOLT (1 pc)
GOVERNOR LEVER
SHAFT
OIL FILTER
OIL PUMP FILTER
STEEL BALL
SPRING, relief valve
GASKET, aluminum
PLUG, oil relief
FIGURE 5-16.
5-12
Page 45
6.Engine Reassembly
PRECAUTIONS
1. Clean parts thoroughly before reassembly.
A.Make sure the piston, cylinder, crankshaft,
connecting rod and bearings are particu-
larly clean.
2.Scrape off all carbon deposits from cylinder
head, top of piston and piston ring grooves.
3.Check lips of oil seals. Replace any oil seal
where the lip is damaged. Apply grease to the
lip before reassembly.
4. Replace all gaskets with new ones.
5. If necessary, replace keys, pins, bolts, nuts,
etc.
6.Torque bolts and nuts to specification. Refer to
the “TORQUE SPECIFICATIONS” Table in
Section 2.
7.Apply oil to rotating and meshing parts.
8. Check and adjust clearances and end plays
where specified in this section.
SPECIAL TOOLS
No special tools are required for disassembly of the
engine. Metric-size sockets and wrenches will be
needed. A ring spreader will be needed to install
pistion rings, and a ring compressor will be used to
install the pistons.
BREAK–IN OPERATION
An engine that has been completely overhauled
with new piston, rings, valves and connecting rods
should be thoroughly broken-in before being placed
into service. Good bearing surfaces and running
clearances between the various parts can be estab-
lished only by operating the engine under reduced
speed and loads for a period of time.
To break-in the engine:
1. Run the engine at 2500 rpm, without a load, for
10 minutes.
2.Run the engine at 3,000 rpm for 10 minutes.
3.Run the engine at 3,600 rpm for 10 minutes.
4. Run the engine with a load of 8 HP at 3,600 rpm
for 30 minutes.
5. Run the engine with a load of 16 HP at 3,600
rpm for 30 minutes.
While the engine is being tested, check for fuel and
oil leaks.
Make final carburetor adjustments and regulate the
engine operating speed.
After the first 20 hours of normal operation, change
the oil and oil filter.
PRE-ASSEMBLY
Inspect and pre-assemble the engine subassem-
blies prior to replacing in crankcase.
Crankcase
1. Replace oil pump filter in bottom of crankcase
(Figure 5-16).
2.Insert ball and relief valve spring into bottom of
crankcase. Tighten plug to specified torque.
Torque the relief valve plug between 10.9 and
18.1 ft/lbs (11.8 – 14.7 N " m).
3.Replace the governor lever shaft and secure
with a snap pin and washer.
4. Replace the oil drain valve, if removed, and the
oil filter.
6-1
Page 46
Cylinder Heads, Valves and Rocker Arms
• Clean valves and wash cylinder head thor-
oughly.
• Remove carbon and gum deposits from the
valves, seats, ports and guides.
• Inspect valves, valve seats and valve guides.
• Replace valves that are badly burned, pitted
or warped.
• Valve guides should be replaced when valve
stem clearance exceeds specifications. (Refer to the DIMENSIONS AND CLEARANCES
tables in Section 2 for clearance specifications.)
If clearance has been exceeded, draw valve
guides out and press new guides in. After
replacing valves and guides, lap valves in
place until a uniform ring shows around the
face of the valve.
1. Insert an oil seal to the intake valve guide only
(Figure 6-1).
2.Apply oil to washer, valve spring and valve
stem. Place cylinder head on flat table and
install washer, valve spring, valve and spring
retainer (Figure 6-1).
3.Install rocker arm and shaft.
Pistons and Connecting Rods
ROCKER
ARM
SPRING
RETAINER
COLLET
–VALVE
VALVE
SPRING
WASHER
OIL SEAL
ROCKER
SHAFT
EXHAUST
VALVE
INTAKE
VALVE
FIGURE 6-1.
1. Install the oil control ring first, then the second
ring and top ring. Using a piston ring spreader
expand rings just far enough to slip over piston
and into the correct groove. Use care not to dis-
tort ring (Figure 6-2).
A.Install the second ring with punched mark
beside the gap on the top side.
B.Top ring can be placed either way.
C.As for oil ring, rails should be placed on
and below the expander.
D.Arrange gaps of piston rings as shown in
Figure 6-5.
Compression rings may have a dot or the word
“top” on one side of the ring to indicate which
side faces the top of the piston. Unmarked pis-
ton rings can be installed either way.
2.Apply oil to the small end of connecting rod and
piston pin. Position the piston on its respective
rod and install the pin.
3.To secure the pin, place retaining rings on each
side of the pin.
6-2
Page 47
1
2
3
TOP
RING
SECOND
RING
OIL
RING
BARREL
TAPER
COMBINATION
RING
WASHER : 2 pcs.
GOVERNOR
GEAR SHAFT
GOVERNOR
SLEEVE
GOVERNOR
THRUST
BEARING
1
2
GEAR
3
FIGURE 6-2.
Main bearing cover and governor gear
1. Insert washers onto governor gear shaft.
2.Insert governor gear along with sleeve into
governor gear shaft (Figure 6-3).
RE-ASSEMBLY PROCEDURES
Crankshaft
1. Install crankshaft into crankcase (Figure 6-4).
NOTE: Apply adequate oil to bearing portion of
crankcase. For easy installation, put crankcase
on box or wood blocks.
MAIN BEARING COVER
FIGURE 6-3.
CRANKSHAFT
FIGURE 6-4.
Pistons and Connecting Rods
1. Install each piston and connecting rod assem-
bly into cylinder by using a piston ring compres-
sor to hold piston rings.
A.The “1” mark on the connecting rod for #1
cylinder and “2” mark for #2 cylinder
should face towards the flywheel when in-
serted (Figure 6-5).
B.Apply enough oil to piston rings, connect-
ing rod bearings (large end) and cylinder
bore before assembly.
6-3
Page 48
PISTON RING COMPRESSOR
CONNECTING ROD
ALIGNMENT MARKS
1
”1” MARK
TOP RING
OIL RING
FIGURE 6-5.
SECOND RING
RING GAP
DIAGRAM
2.Temporary install the key and flywheel on the
crankshaft, then turn crankshaft to BDC (bot-
tom dead center). Lightly tap the top of the pis-
ton until large end of the rod meets the pin on
the crankshaft.
3.Match the alignment marks on the connecting
rod cap to connecting rod and clinch together.
(Figure 6-6). Tighten the connecting rod bolts
to the specified torque.
FIGURE 6-6.
Tappets and Camshaft
1. Grease tappets and insert into their original
position. Push tappets in all the way to avoid
damage to the camshaft.
2.Lubricate bearing surfaces of the camshaft.
Install camshaft into the crankcase aligning the
timing mark on the camshaft to the timing mark
on the crankshaft gear. See Figure 6-7.
CAUTION
engine malfunction.
Incorrect alignment will cause
Torque the (2) M8 bolts between 16.3 and 19.9 ft/
lbs (22.1 – 27.0 N " m).
4. Check for free movement of piston and connecting rod by turning crankshaft slowly.
6-4
FIGURE 6-7.
3.Adjust the side clearance.
A.Measure the end play of crankshaft and
camshaft. Adjust end play between 0.006"
and 0.013 " (0.152 – 0.330mm) using the
proper spacer.
B.Spacer Calculation: (Refer to FIgure 6-8.)
2
# A " + 0.014" – # B " (
1
)
Page 49
MAIN BEARING
COVER
SPACER
CRANKSHAFT
GEAR
FIGURE 6-8.
0.014” (0.36mm)
(Thickness with
gasket tightened)
CRANKCASE
Main Bearing Cover
1. Place an oil seal guide onto PTO shaft to avoid
damaging the main bearing cover oil seal.
Make sure the governor lever shaft and the
oil pump filter are installed in the crankcase.
2.Place gasket onto the mating surface of crank-
case.
3.Using a soft hammer, tap the cover until it
touches the crankcase mating surface. Make
sure the governor gear and camshaft gear are
properly engaged.
4. Lubricate the oil seal lip and bearing surfaces,
and install main bearing cover. Tighten bolts
gradually in an even pattern to the specified
torque.
Torque the (10) M8 flange bolts between 12.3
and 13.7 ft/lbs (16.7 – 18.6N " m ).
5. Rotate crankshaft slowly and check for smooth
operation and side clearance.
Oil Pump and Cover
1. Apply oil to inner and outer rotors of oil pump
and position them on the crankshaft.
2.Position an o-ring in onto crankcase (Figure 6-9).
4. Install the oil pump cover with arrow mark
pointing upwards.
INNER ROTOR
OUTER ROTOR
O–RING
OIL SEAL
FLANGE BOLT
FIGURE 6-9.
ARROW MARK
OIL PUMP
COVER
Cylinder Heads
NOTE: Inspect the dwell pin and replace if damaged.
1. Place new head gaskets onto crankcase.
2.Install #1 and #2 cylinder heads. Tighten bolts
gradually in an even pattern to the specified
torque.
3.Grease the oil seal and install on the oil pump
cover.
Torque the(4) M10 flange bolts between 24.6 and
30.4 ft/lb (33.3 – 41.2 N " m) on each cylinder head.
6-5
Page 50
Push Rods
FEELER
GAUGE
3.Tighten locknut to the specified torque.
1. Rotate the crankshaft until the tappets are at
their lowest position.
2.Loosen the rocker arm adjustment setscrews.
3.Insert the push rods into the concave end of the
tappet. With the valve spring depressed, Insert
the other end of the push rod into the concave
part of the rocker arm adjustment screws.
4. Temporally tighten the adjusting screws.
Valve Clearance Adjustment
NOTE: Temporally place the flywheel in position for
easier operation.
1. Rotate crankshaft clockwise to the TDC (top
dead center) of compression stroke by match-
ing the “T” mark on the flywheel with the “1”
mark on #1 cylinder head (Figure 6-11).
2.Loosen locknut on rocker arm and turn adjusting screw to adjust the clearance between
rocker arm and valve stem end. (Figure 6-10.)
Torque the (2) M8 locknuts between 7.2 and 10.1
ft/lb (9.8 – 13.7 N " m) on each rocker arm set.
4. Adjust valve clearance on the #2 cylinder side
in the same manner.
5. Rotate crankshaft several times and check the
valve clearance again. Make final adjustments
to each valve, if necessary.
Valve Clearance: 0.004” (0.085 – 0.115 mm) Cold
condition
“2” MARK
FLYWHEEL
FIGURE 6-10.
#1 CYLINDER#2 CYLINDER
“1” MARK
“T” MARK
FIGURE 6-11.
6-6
Page 51
Rocker Arm Covers
CHARGE COIL
FLANGE
WIRES AT
2 O’CLOCK
BOLT
STARTER
TORQUE NOTES:
Install each rocker arm cover using new gaskets.
Attach lift hooks to the upper bolts on each cover.
Tighten bolts to the specified torque.
Torque the (4) M6 flange bolts between 24.4 and 43.2
in/lbs (2.9 – 4.9 N " m) on each cover.
Breather Plate and Cover
The crankcase breather prevents pressure from
building up in the crankcase. It also prevents oil
contamination by removing moisture or gasoline
vapors and other harmful blow-by materials from
the crankcase. These vapors are routed to the car-
buretor where they are mixed with incoming air and
burned in the combustion chamber. A sticky breath-
er valve can cause oil leaks, high oil consumption,
rough idle, reduced engine power, and a rapid
formation of sludge and varnish within the engine.
1. Attach breather plate (breather valve) and
breather cover to crankcase using the proper
gaskets.
2.Position the breather plate so the reed valve is
opens away from the cylinder head. (Figure
6-12.)
New Plugs: between 8.7 and 10.8 ft/lbs (11.8 –
14.7 N " m).
Used Plugs: between 16.6 and 19.5 ft/lbs (22.5 –
26.5 N " m).
GASKET
BREATHER
GASKET, breather
BREATHER
COVER
REED
VALVE
FIGURE 6-12.
M6 FLANGE
BOLT : 2 pcs.
Charge Coil
1. Install charge coil with the wires routed at the
2-o’clock position (Figure 6-13).
3.Tighten the breather cover bolts to the speci-
Replace the breather if it’s broken or cracked, or if
the crankcase pressure is indicated by oil leaks at
the seals or excessive oil in the air cleaner housing.
Spark Plugs
1. Reinstall the spark plugs to each cylinder.
2.Use type NGK–BP6ES or BRP6ES (CHAM-
3.Torque spark plugs as specified below.
fied torque.
Torque the (2) M6 flange bolts between 24.6 and
43.2 in/lbs (2.9 – 4.9 N " m).
NOTE: Over-tightening the bolts will result in
gasket damage. Replace torn or damaged gaskets if necessary.
PION – N9YC or RN9YC).
FIGURE 6-13.
2.Tighten the bolts and washers gradually in an
even pattern to the specified torque (Figure
6-13).
Torque the (4) M5 bolts between 13.2 and 30
in/lbs (1.5 – 3.4N " m).
6-7
Page 52
Starter Motor
1. Install starter and solenoid assembly. Tighten
the flange bolts to specified torque.
Torque the M18 nut between 61.5 and 68.7 ft/lbs
(83.3 – 93.1N " m).
Ignition Coils, Cylinder Baffles
Torque the (2) M8 bolts between 12.3 and 13.7
ft/lbs (16.7 – 18.6N " m).
Intake Manifold
1. Place a stainless steel gasket onto both #1 and
#2 cylinder heads and install intake manifold
onto engine studs. Secure with flange nuts to
the specified torque.
Torque the (2) M8 flange nuts between 12.3 and
13.7 ft/lbs (16.7 – 18.6N " m).
MANIFOLD
GASKET
M8 FLANGE NUT : 2 pcs.
INTAKE MANIFOLD
M8 FLANGE
NUT : 2 pcs.
MANIFOLD
GASKET
1. Install the ignition coils onto crankcase. Fingertighten the M6 bolts and washers.
2.Using a feeler gauge, adjust the gap between
the coil and flywheel between 0.012 – 0.021”
(0.3 – 0.5mm).
3.Tignten bolts the the specified torque.
Torque the (2) M6 bolts between 5.1 and 6.5
ft/lbs (6.9 – 8.8N " m).
4. Connect wiring from the stop diodes to the pri-
mary terminals on the ignition coils (Figure
6-15).
5. Secure wires with cable ties and route wire
bundles between the number 2 cylinder and
the oil filter housing.
THICKNESS GAUGE IGNITION COIL
WIRE
FIGURE 6-14.
Flywheel
1. Remove the M18 nut and washers from the ta-
pered end of the crankshaft.
2.Place woodruff key in the keyway of crankshaft.
3.Wipe off oil and grease thoroughly from the
crankshaft and flywheel center hole.
4. Install flywheel to crankshaft and tighten fly-
wheel nut with spring washer and washer.
Tighten the flywheel nut to the specified torque.
Carburetor
6-8
Fig. 5 –4 3
FIGURE 6-15.
STOP DIODE
6.Replace all four cylinder baffles secured with
M6 flange bolts. (Refer to Figure 5-5.)
1. Place a new gasket onto the intake manifold
and install carburetor. Tighten the bolts to the
specified torque.
Torque the (2) M8 flange bolts between 12.3 and
13.7 ft/lbs (16.7 – 18.6N " m).
Page 53
Governor Lever, Control Solenoid
GOVERNOR
LEVER
GOVERNOR SHAFT
ROD SPRING
GOVERNOR ROD THROTTLE LEVER
LOCKING BOLT
1. Attach governor rod and rod spring between
the governor lever and carburetor throttle lever.
Insert the governor lever on governor lever
shaft (Figure 6-16). Finger-tighten the M6 locking bolt, washer and square nut.
2.Reinstall the speed and choke linkage mounting bracket and secure with (3) M6 flange bolts.
3.Attach one end of the governor spring on the
speed control link and the other end on the fifth
hole of the governor lever (Figure 6-17).
Follow the adjustment procedures for the carbure-
tor in Section 6 of the Operator’s Manual.
CHOKE
CONTROL
RETURN
SPRING
GOVERNOR
SPRING
SPEED
CONTROL
LINK
FIGURE 6-17.
ROD
CHOKE
LINK
M6 NUT
FIGURE 6-16.
4. Attach the choke control rod and the return
spring between the choke control lever (on car-
buretor) and the choke control link (Figure
6-17).
5. Replace the speed control solenoid to the gear
case cover.
Adjust Governor
1. Push the speed control lever clockwise to the
high speed position and tighten the nut.
2.Make sure the governor lever is pulled by the
governor spring and the carburetor valve is ful-
ly open.
3.Turn governor shaft counterclockwise all the
way and tighten lock bolt to secure the lever on
the shaft (Figure 6-18).
GOVERNOR LEVER
GOVERNOR SHAFT
FIGURE 6-18.
Blower Housing, Fuel Pump
1. Attach blower housing to crankcase and se-
cure evenly with (8) M6 flange bolts.
2.Install fuel pump and mounting bracket onto
the blower housing. Connect fuel hose to the
carburetor and pulse hose to the crankcase.
6-9
Page 54
Air Cleaner
Wiring
1. Connect breather hose to air cleaner base.
2.Install air cleaner base onto carburetor.
3.Connect breather hose to #1 cylinder head.
4. Place air cleaner element along with urethane
form onto base.
5. Install air cleaner cover and secure with knob.
Oil Pressure Switch and Oil Filter
1. Install oil pressure switch into the elbow con-
nector on crankcase. Tighten to the specified
torque.
Torque the pressure switch between 4.3 and 7.2
ft/lbs (5.9 – 9.8N " m).
2.Apply a thin coat of oil to the rubber gasket on
the oil filter canister. Hand-tighten about 3/4
turns after the gasket touches the crankcase.
Torque the oil filter to approximately 9 ft/lbs
(12.3N " m).
1. Attach the wire holder, relay and connector,
and ground terminals to the engine crankcase
under the #1 cylinder baffle. (See Figure 6-19.)
2.Route the ground wires and connector wires
threw the wire holder.
3.Secure the wires to the intake manifold with
cable ties.
4. Attach the spark plug wires onto each plug.
5. Route wire bundle up through the cable holder
mounted on the Control Solenoid.
FINAL CHECKS
1. Check for loose bolts and nuts. Make sure all
electric wiring connections are secure.
2.Reconnect the battery, ( + ) positive terminal
first.
3.Connect the fuel supply hose to the supply.
Note: To prevent fuel from flooding the carbure-
tor, the valve must be closed when the engine is
not running.
4. Refill engine oil and start the engine. After oil lubricates the oil passages and oil filter, turn off
engine and recheck the oil level.
WIRE
HOLDER
FIGURE 6-19.
GROUND
TERMINALS
(Not on all
models)
ELBOW
PRESSURE
SWITCH
RELAY and
CONNECTOR
(Not on all models)
6-10
CAUTION
Starting the engine without oil
will cause severe engine damage. Always
keep the engine oil level between the Full
and Add marks on the dipstick.
CAUTION
Overcranking the engine can
cause starter damage. Do not engage start-
er for longer than 30 seconds. If engine
does not start, allow 5 minutes for starter to
cool between cranking intervals.
WARNING
Crankcase pressure can blow
hot engine oil out the fill tube causing se-
vere burns. Always stop the engine before
removing the oil fill cap or the oil gauge.
NOTE: Total engine oil capacity is about 1.64 qt
(1.55 L).
Use “SE” (API classification) or higher grade en-
gine oil.
Page 55
ONAN CORPORATION
1400 73RD AVENUE N.E.
MINNEAPOLIS, MN 55432
FAX: 763-528-7229
ONAN IS A REGISTERED TRADEMARK OF ONAN CORPORATION
CUMMINS IS A REGISTERED TRADEMARK OF CUMMINS ENGINE COMPANY
Loading...