Onan CCK User manual

Orion
Service
Manual
Engines
927-0754
3-86 (Spec A-J)
Replaces
9-84 (Spec A-J)
Printed in USX

Safety Precautions
It is recommended that you read your engine manual and
become thoroughly acquainted with your equipment be¬
fore you start the engine.
This symbol Is used throughout this
manual to warn of possible serious
persons! injury.
This symbol refers to possible equip¬
ment damage.
Fuels, electrical equipment, batteries, exhaust gases and
moving parts present potential hazards that could result in
serious, personal injury. Take care in following these
recommended procedures. ’
Safety Codes
• All local, state and federal codes should be consulted
and complied with.
• This engine is not designed or intended for use in
aircraft. Any such use is at the owner’s sole risk.
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 when close to hot ex¬
hausts. moving parts, etc.
Protect Against Moving Parts
• Do not wear loose clothing in the vicinity of moving
parts, such as PTO shafts, flywheels, blowers, coup¬
lings, fans, belts, etc.
• Keep your hands away from moving parts.
Batteries
• Before starting work on the engine, disconnect batter¬
ies to prevent inadvertent starting of the engine.
• DO NOT SMOKE white servicing batteries. Lead acid
batteries give off 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.
Fuel System
• DO NOT fill fuel tanks while engine is 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.
« Fuel lines must be of steel piping, adequately secured,
and free from leaks. Piping at the engine should be
approved flexible line. Do not use copper piping for
flexible lines as copper will work harden and become
brittle enough to break.
• Be sure all fuel supplies have a positive shutoff valve.
Exhaust System
• Exhaust products of any internal combustion engine
are toxic and'can cause injury, or death if inhaled. All
engine applications, especially those within a confined
area, should be equipped with an exhaust system to
discharge gases to the outside atmosphere.
• Do not use exhaust gases to heat a compartment.
• Make sure that your exhaust system is free of leaks.
Ensure that exhaust manifolds are secure and are not
warped by botts unevenly torqued.
Exhaust Gas is Deadly!
Exhaust gases contain carbon monoxide, a poisonous gas
that might cause unconsciousness and death. It is an
odorless and colorless gas formed during combustion of
hydrocarbon fuels. Symptoms of carbon monoxide poi¬
soning are:
• Dizziness • Vomiting
• Headache • Muscular Twitching
• Weakness and Sleepiness • 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 inspections of the
complete exhaust system. If you notice a change in the
sound or appearance of exhaust system, shut the unit down
immediately and have it inspected and repaired at once by a
competent mechanic.
Cooling System
• Coolants under pressure have a higher boiling point
than water. DO NOT open a radiator pressure cap when
coolant temperature is above 212° F (100°C) or while
engine is running.
Keep the Unit and Surrounding Area Clean
• Make sure that oily rags are not left on or near the
engine.
• Remove all unnecessary grease and oil from the unit
Accumulated grease and oil can cause overheating and
subsequent engine damage and present a potential fire
hazard.
E-4

Table of Contents
Genera! Information..
Specifications ...
Dimensions and Clearances.4
Assembly Torques and Special Tools. 6
Engine Troubleshooting.7
Starting..
Installation Guidelines .9
Oil System . 1 4
Governor System..
Fuel System.21
Ignition System..
Battery Charging System ... 4 1
Starting System..
Manual Starter. 5 9
Engine Disassembly.53
Special Equipment..
WAKNINO |
INCORRECT SERVICE OR REPLACEMENT OF PARTS MIGHT RESULT IN
SEVERE PERSONAL INJURY AND/OR EQUIPMENT DAMAGE. SERVICE
PERSONNEL MUST BE QUALIFIED TO PERFORM ELECTRICAL AND/OR
MECHANICAL SERVICE.
1

General Information
mi-
introduction
ENGINE MODEL REFERENCE
This manual deals with specific mechanical and elec¬
trical information needed by engine mechanics for
troubleshooting, servicing, repairing, or overhauling
the engine.
Use the table of contents for a quick reference to the
separate engine system sections.
The troubleshooting guide is provided as a quick
reference for locating and correcting engine trouble.
The illustrations and procedures presented in each
section apply to the engines listed on the cover. The
flywheel end of the engine is the front end so right
and left sides are determined by viewing the engine
from the front.
The disassembly section contains major overhaul
procedures for step by step removal, disassembly,
inspection, repair and assembly of the engine
components.
If a major repair or an overhaul is necessary, a compe¬
tent mechanic should either do the job or supervise
and check the work of the mechanic assigned to do
the job to ensure that alt dimensions, clearances and
torque values are within the specified tolerances.
A parts catalog (available at the dealer level) contains
detailed exploded views of each assembly and the
individual piece part numbers and their proper names
for ordering replacement parts.
Use only Genuine Onan replacement parts to ensure
quality and the best possible repair and overhaul
results. When ordering parts, always use the com¬
plete Model and Spec number as well as the Serial
number shown on the nameplate.
Identify your model by referring to the MODEL and
SPEC (specification) NO. as shown on the unit
nameplate. Always use this number and the engine
serial number when making referencetoyourengine.
How to interpret MODEL and SPEC NO. on generator
set engines.
CCK
2
F
T
1. Indicates kilowatt rating.
2. Series identification.
3. Voltage code of the generator.
4 Method of starting: A-automatic, R-remote elect¬
ric starting, and E-electric starting.
5. Factory code for designating optional equipment,
if any.
6 Specification letter which advances when the fac¬
tory makes production modifications.
How to interpret MODEL and SPEC NO. on industrial
engines.
CCK MS / 3199
1 2 3
T
4
t. Factory code for general identification purposes.
2 Specific Type*
MS-ELECTRIC starting with stub shaft, starter
and generator.
3, Factory code for optional equipment supplied.
4. Specification (Spec Letter) advances with factory
production modification.
2

Specifications
This manual contains Si metric equivalents that follow immediately in parentheses
after the U.S. customary units of measure.
SPECIFICATION
Number of Cylinders
Bore
Stroke
Displacement
Compression Ratio_
Rated Speed (Maximum)
Power at
Rated Speed_
Oil Filter
Oil Capacity Without
Filter _
Oil Capacity With
Filter Change
Crankshaft Rotation
(viewed from flywheel)
Governor
Valve Clearance (Cold)
Intake
Exhaust
Spark Plug Gap (Gas)
Spark Plug Gap (Gasoline)
UNIT OF
MEASURE
3.000
(76.2)
49.8
(816)
5.5 to 1
2700
12.9
(9.6)
Full Flow
3.0
(2.8)0
3.5
(3.3)©
Clockwise
Mechanical
SERIES
CCKA
2
3.250
(82.55)
49.8
(816)
7.0 to 1
3600
Full Flow
3.0
(2.8)0
Clockwise
Mechanical
0.007
(0.18)
0.016
(0.41)
CCKB
2
3.000
(76.2)
49.8
(816)
7.0 to 1
3900
20.0
(14.9)
Full Flow
3.5
(3.3)
Clockwise
Mechanical
0.007
(0.18)
0.016
(0.41)
Breaker Point Gap - Static
in
0.020
0.020
0.020
(Full Separation and Engine Cold)
(mm) (0.51)
(0.51) (0.51)
Ignition Timing
All Models
BTC
19°
Gaseous Fuel
BTC
Gasoline Fuel
BTC
24°
24°
Gasoline Fuel (Static)
ATC
1°®
o ^
1°®
Gasoline Fuel (Static or Running)
BTC
20° ©
20° ®
Gasoline Fuel Running
BTC
24°®®
24° ©
Q' - Add 0.5 quart (0.47 litre) for electric start modeis.
© - Magneto Ignition
® - With Spark Advance
© - Battery Ignition
© - Magneto Ignition with Spark Advance
3

Dimensions and Clearances
All clearances given at room temperature of 70°F (21 °C). All dimensions In Inches (approximate millimetre dimensions in
parentheses) unless otherwise specified.
DESCRIPTION MINIMUM MAXIMUM
CYLINDER BLOCK
Inches
(mm) Indies
(mm)
Cylinder Bore Honed Diameter...
Maximum Allowable
. 3.2490
(82.525)
3.2500
(82.550)
Taper.
0.005 (0.127)
Out-of-Round . 0.002 (0.051)
Main Bearing Inside Diameter {Without bearing)..
. 2.187
(55.55)
2.188
(55.58)
Main Bearing Inside Diameter CCK (Installed).
. 2.0020 (50.85)
2.0030
(50.88)
Main Bearing Inside Diameter CCKA/CCKB (Installed) .
. 2.0015 (50.84)
2.0040 (50.90)
Camshaft Bearing Bore (Bearing installed)....
CRANKSHAFT
. 1.3760
(34.95)
1.3770 (34,98)
Main Bearing Journal Diameter... . 1.9992
(50.78)
2.0000
(50.80)
Main Bearing Clearance. . 0.0025
(0.064)
0.0038 (0.097)
Connecting Rod Journal Diameter.
. 1.6252 (4138} 1.6260
(41.30)
Crankshaft End Play.
CONNECTING ROD
Large Bore Diameter (Without bearing installed
. 0.006 (0.152) 0.012 (0305)
and rod bolts property torqued] .... . 1.7505 (44.46) 1.7510 (44.48)
Connecting Rod Side Clearance......, . 0.0020 (0.051) 0.0160 (0.406)
Piston Pin Bushing Bore {Without bearing).
Piston Pin Bushing Bore with Bearing,
. 0.8115 (20.61) 0.8125 (20.64)
(Finished bore).
Bearing to Crankshaft Clearance
. 0.7504
(19.05) 0.7508 (19.07)
Nodular Iron Rod...
. 0.0005 (0.013) 0.0023
(0.058)
Aluminum Rod.
CAMSHAFT
...... 0.0020
(0.051) 0.0033 (0.084)
Bearing Journal Diameter. . 13740
{34.90}
13745
(34.91)
Bearing Clearance.
. 0.0015 (0J038) 0.0030 (0.076)
End Play.
...... 0.0030
(0.076) 0.0120 (0305)
Camshaft Lift.
PISTON
Clearance in Cylinder
0.300
(7.62)
Measure 90° to pin 0.10 inch below oil ring...
Clearance in Cylinder (CCKB with 112-0073 piston)
. 0.0025
(0.064)
0.0045
(0.114)
Measure 90° to pin 0.10 inch below oil ring..
. 0.0060 (0.150)
0.0080 (0300)
Piston Pin Bore.......
Ring Groove Width
. 0.7502 {19.055)
0.7506
(19.065)
Top 1 Compression Ring .
. 0.0960 {2.438) 0.0970
(2.464)
No. 2 Compression Ring..
. 0.0955 {2.426) 0.0965
(2.451)
No. 3 Oil Control Ring...
.. 0.188
(4.775)
0.189 (4.801)
4

DESCRIPTION
MINIMUM MAXIMUM
PISTON PIN
Inches (mm) inches (mm)
Clearance in Piston.
Thumb Push Fit
Clearance in Connecting Rod ... *... ........ 0.0002
(0.005) 0.0007
(0.018)
Diameter.
PISTON RINGS
Clearance
.. 0.7500
(19.05) 0.7502 (19.06)
Top Groove.... . 0.002
(0.051)
0.008
(0.203)
Ring End Gap in Cylinder.
INTAKE VALVE
. 0.010 (0.254) 0.020 (0.508)
Stem Diameter...
. 0.3425
(8.70) 0.3430 (8-71)
Clearance (Stem to Guide) .
Valve Face Angle.
INTAKE VALVE SEAT
. 0.0010 (0.025) 0.0025
44°
(0.064)
Valve Seat Width.
Valve Seat Angle.
EXHAUST VALVE
. 0.031 (0.787)
0.047
45°
(1.194)
Stem Diameter. . 0.3410 (8.661)
0.3415 (8.674)
Clearance (Stem to Guide).
Valve Face Angie.
EXHAUST VALVE SEAT
. 0.0025 (0.064)
0.004
44°
(0.102)
Seat Cylinder Head Bore Diameter.
. 1.1890 (30.20) 1.1900
(30.23)
Seat Outside Diameter...
. 1.1920 (30.28)
1.1930
(30.30)
Valve Seat Width.
Valve Seat Angle.
VALVE GUIDE
. 0.031 (0.787) 0.047
45°
(1.194)
Inside Diameter.....
TAPPET
. 0.344
(8.74)
0.346
(8.79)
Body Diameter.
. 0.7475
(18.99) 0.7480
(19.00)
Bore Diameter. ........ 0.7505
(19.06) 0.7515
(19.09)
Clearance in Bore.....
VALVE SPRINGS INTAKE AND EXHAUST
. 0.0015
(0.038) 0.003
(0.076)
Valve Spring Free Length (Approx.)...
Valve Spring Length
1.662 (42.21)
Valve Open.....
1.125' (28.58)
Valve Closed. 1.375 (34.93)
Spring Load @ 1.375 inch (Valve Closed)........ ........ 38 ib. (17 kg)
42 ib.
(19 kg)
Spring Load @1.125 inch (Valve Open).
GEAR BACKLASH
. 71 Ib
(32 kg)
79 Ib (36 kg)
Timing Gear. . 0.002 (0.051) 0.003
(0.076)
Oil Pump Gear..... . 0.002 (0.051)
0.005 (0.127)
5

Assembly Torques
The torque values given in Table 1 have been deter¬
mined for the specific applications. Standard torque
values must not be used where those listed in Table 1
apply. The engine assembly torques given here will
assure proper tightness without danger of stripping
threads. All threads must be clean and lubricated with
new engine oil before torquing.
Check all studs, nuts, and capscrews, and tighten as
required to keep them from working loose. Refer to
the PARTS MANUAL for the location of washers and
capscrews.
TABLE 1.
TORQUE
DESCRIPTION
SPECIFICATION
Ft-Lb. Nm
Cylinder Head Capscrews_
29-31
(39-42)
Rear Bearing Plate.,.
Connecting Rod Bolt
20-25
(27-34)
Iron Rod ...
27-29 (37-39)
Aluminum Rod.
24-26
(33-35)
Flywheel Capscrew.
Starter Mounting Bracket to
35-40
(48-54)
Oil Base Screws.
25-35 (34-47)
Gear Case Cover..
10-13 (14-18)
Oil Pump...
7-9
(10-12)
intake Manifold ..
15-20 (20-27)
Exhaust Manifold.
14-17 (19-23)
Oil Base.
43-48 (58-65)
Special Tools
The following special tools are available from Onan.
For further information see TOOL CATALOG
9(XHmsL
YaNe Seat Driver
VaNe Guide Driver
OH Guide arid Driver
Combination Bearing Remover (Main and Cam)
Combination Bearing Driver (Main and Cam)
Ffywheet Putter
8

Engine T roubleshooting
7

Starting
PRE-STARTING
Preparations for the initial and each additional star¬
ting operation should include careful checks of the
oil, fuel, cooling, and electrical systems. The cylinder
air housing door should be closed withal! airshrouds
in place.
Crankcase Oil: Be sure the crankcase has been filled
with oil to the “FULL” mark on the oil level indicator,
Figure 1. Use oil with the API (American Petroleum
Institute) designation SE or SE/CC. Do not use an oil
with the designation CD unless it is also designated
SE and the oil manufacturer certifies it will perform
satisfactorily in gasoline engines.
For gaseous operation, use an ashless or low-ash
detergent oil specifically made for gaseous-fueled
engines.
CAP AND OIL
LEVEL INDICATOR
KEEP OIL
AT THIS LEVEL.
NEVER OPERATE
ENGINE WITH OIL
BELOW THIS LEVEL.
A874
-FULL
ALWAYS REPLACE
CAP TIGHTLY, OR
OIL LEAKAGE HAY
OCCUR.
FIGURE 1. OIL LEVEL INDICATOR
WARNING ) Crankcase pressure could blow out
fj 0 f 0 /7 and cause serious burns. Do
NOT check oil while the engine is operating.
OIL CAPACITIES
Electric Start
3-1/2 qts. (3.31 litre)
4 qts. (3.8 litre with filter)
Manual Start
3 qts. (2.8 litre)
3-1/2 qts. (3.3 litre with filter)
Engine oil should always bedrained when the engine
is warm. Remove pipe plug to drain engine oil.
Recommended Fuel: Use clean, fresh, regular grade,
automotive gasoline. Do not use highly-leaded
premium types.
For new engines, the most satisfactory results are
obtained by using nonleaded gasoline. For older
engines that have previously used leaded gasoline,
heads must be taken off and all lead deposits removed
from engine before switching to nonleaded gasoline.
I^CAUTION^ If lead deposits are not removed
—*~*-^*-*~& irom engine before switching from
leaded to nonleaded gasoline, pre-ignition could
occur causing severe damage to the engine.
WARNING I Spilled fuel might Ignite and cause
serious personal Injury or death.
Never fill the fuel tank when the engine is running.
STARTING
Electric Start
1. Move the ignition switch to ON.
2. Push the START button to crank the engine.
Manual Start
1. Engine priming before starting is shown in Figure
5 (manual start only).
2. Pull the choke control about 3/4 of the way closed
or as necessary according to temperature con¬
ditions.
3. Pull the start rope with a fast steady pull to crank
the engine. Do not jerk or let rope snap back
under its own power.
4. As the engine warms up, adjust the choke
gradually to its fully open position.
APPLYING LOAD
Apply load to a new or reconditioned engine gradual¬
ly in about four steps; not less than 30 minutes
running time for each step. Start with 1/4 load, then
1/2, 3/4 and full-load.
STOPPING THE ENGINE
When possible, disconnect all load before stopping
the engine. Engines equipped with battery ignition
are stopped by setting the ignition switch to the off
position.
Open the fuel line valve (when used) and operate
primer to assure fuel supply after filling an empty
tank.
Engines equipped with magneto ignition are stopped
by pushing the stop button (located on the blower
housing). Hold in until engine completely stops.

Installation Guidelines
VENTILATION
The engine must be provided with asupply of fresh air
for cooling and for combustion. Figure 2.
Pressure Cooled Engine: Position the air inlet open¬
ing directly in front of the engine and as close to the
eng ine blower wheel as possible. The area of the inlet
should be not less than 65 square inches (419 cm 2 ). if
louvers or grill work are used, increase the area to
compensate for the reduced air flow. Provide extra
ventilation if the driven load generates heat during
operation.
The heated air outlet must allow the heated air to
escape freely and prevent recirculation with the
cooling air. A duct between the compartment air inlet
and the engine blower housing may be necessary.
Locate the air outlet opposite the intakeorat least at a
90 degree angle. The area of the outlet should be at
least 15 percent larger than that of the inlet Allow
sufficient room on ail sides to permit access for
servicing.
Open Air Installation: For installations where the
engine is operated outside, ventilation will be no
problem. However, in protecting the engine from the
elements, see that nothing obstructs the flow of air
around the engine.
Vacu-Flo Cooled Engine: The Vacu-Fio equipped
engine uses separate flywheel and a blowerwheelto
puli cool air into the engine shroud and over the
cooling fins and surfaces of the engine. Figure 2.The
heated air is directed through an airtight scroll which
encases the blower. The scroll may be positioned to
discharge heated air in the 12 o’clock or 3 o’clock
direction, (Figure 3). The scroll outlet has a mesh-
type screen for safety.
The outlet of the VACU-FLO scroll
must not be restricted or overheat¬
ing wUI result. Engine overheating can cause troubles
ranging from vapor lock to scored pistons and
cylinders.
The area of the air inlet must be at least 140 square
inches (903 m 2 ). If a filter, grille, or louvers are used,
the inlet opening must be increased accordingly. The
air outlet opening should be located as close to the
engine as possible.
FIGURE 2. AIRFLOW THROUGH ENGINES
If the duct length exceeds 5 feet (127 m) t increase
duct size 30 percent. Use no more than two 90 degree
radius-type (not square-type) elbows if it is necessary
to change air flow direction. When a duct is used
between the sc roil discharge and the outlet vent, its
unobstructed airflow area must be at least as large as
the scroll discharge. The cross-sectional area of the
duct must be increased if air flow is restricted by
bends, long runs, screens or the exhaust pipe.
Exhaust pipes running inside Vacu-Flo ducts should
be covered with asbestos tape.
9

The safety screen used to cover rents must be
1/4-Inch (6.35 mm) mesh or larger to permit
sufficient air flow. All screens and guards must comply with
industrial safety standards that apply to hazardous moving parts to
avoid personal injury.
vibration. Shield the line if it passes through a
combustible wall or partition. If turns are necessary,
use sweeping type {long radius) elbows. Increase one
pipe size {from manifold outlet size) for each ad¬
ditional ten feet in length. Locate the outlet away from
the air intake.
Provide a short canvas section between the engine air outlet and
the external duct or opening, to absorb vibration. If operation in
cold weather is likely, installing a shutter in the air outlet is
advisable. Cold weather can cause overcooling if air flow is not
regulated.
FIGURE 3. VACU-FLO SCROLL POSITIONS
Should a vacu-flo engine chronically overheat, the
most likely sources of the problem are: >
1. Air inlet is obstructed or too small to allow proper
ventilation.
2. Air discharge opening is partially blocked by
external ducts or exhaust systems.
3. Recirculation of heated air into fresh air inlet.
EXHAUST SYSTEM
Inspect the exhaust system regularly. Locate leaks in
muffler and piping while the engine is operating.
Repair all leaks immediately after they are detected
for personnel safety.
CARBURETOR AIR INTAKE
Proper engine efficiency depends upon a supply of
fresh air to the carburetor. Under special conditions,
it may be necessary to move the air cleaner off the
engine, using a iongerconnectionhoseas necessary.
For extremely dusty or dirty conditions, install a
special heavy duty air cleaner.
MOUNTING
There are several acceptable methods of mounting
the engine. Among factors to be considered are:
location, method of coupling the engine to the load,
type of foundation or support, etc. The engine should
be mounted on a level surface if possible. Maximum
operation angle is 15 degrees sideways, 30 degrees
front to rear tilt. If the engine is to operate at an angle,
be sure to re-mark the oil level indicator to compen¬
sate for the tilt.
The type of installation can affect the life of the
engine, the cost of operation and the frequency of
necessary service. Plan the installation carefully to
ensure the best performance.
Because of the great variety of uses, and the many
variations of the engine, these installation instruc¬
tions are typical or general in nature. Use the
installation recommendations given as a general
guide.
CHECKING FOR FUEL AT CARBURETOR
WARNING I Do no * pewit any flame, cigarette,
or other igniter near the fuel system.
Gasoline is highly flammable and potentially explo¬
sive in confined spaces.
warning | Inhalation of exhaust gases might
1 result in serious personal injury or
death. Be sure deadly exhaust gas is piped outside
and away from windows, doors or other inlets to
building.
Use a length of flexible tubing between the engine
exhaust outlet and any rigid piping to absorb engine
1. Look for one or more shutoff devices.
2. Disconnect fuel line at carburetor.
3. If fuel is present at carburetor, check ignition
system or other engine malfunctions.
4. Reconnect fuel line.
CONNECTING TO THE LOAD
The dimensions of various powertakeoff shafts are as
follows.

SHAFT
DIAMETER
LENGTH
KEY SIZE
STD
1-1/2
(38.1 mm)
2-3/4
(69.8 mm)
3/8
(9.5 mm)
Rockford Clutch
1-7/16
(36.51 mm)
3-1/2
(83,9 mm)
3/8
(9.5 mm)
Gear Reduction
1-1/4
(31.75 mm)
2-3/4
(69.85 mm)
1/4
(6.35 mm)
Bell Drive: V-beits are preferable to fiat belts. Consult
a reliable belting supplier for recommendations
regarding size of pulleys, number of belts, etc
required. A typical belt drive installation is shown in
Figure 4.
FIGURE 5. FLEXIBLE COUPLING
KEEP SHAFTS OF ENGINE
AND LOAD PARALLEL,
IDLER PULLEY
KEEP PULLEYS ALIGNED
WITH EACH OTHER
BELT IN TIGHTENED
POSITION - PULLING
LOAD^^^ LOAD
ENGINE //' ■ '“X'C-- pulley
PULLEY
BELT IN LOOSENED
POSITION - NOT
PULLING LOAD
bracket to keep
BELT OFF ENGINE
PULLEY
FIGURE 4, DRIVE BELT INSTALLATION
Comply with the following installation requirements
1. The shafts of the engine and the load must be
parallel with each other,
2. The pulleys of the engine and the load must be in
alignment.
3. Mount the engine pulleys as close to the engine as
possible.
4 If the installation permits, belts should run
horizontally.
5. Some method of disconnecting the load for
starting is recommended. If a clutch is not used, a
belt-tightener idler arrangement can be used. ’
Flexible Coupling: If a flexible coupling engine-to-
load drive is used, the load shaft must be in line and
centered with the engine shaft (Figure 5).
Reduction Gear Drive: Reduction gear drives are
mounted at the factory (when ordered). The method
of connecting the load is the same as when connec¬
ting directly to the engine shaft.
Dram the gear box after the first 100 hours of
operation and refill with fresh lubricant of the
recommended grade. Repeat this procedure every six
months thereafter, or every 100 hours.
Use only SAE 50 motor oil or SAE 90 mineral gear oil.
Do not use lubricants commonly known as extreme
pressure lubricants, hypoid lubricants, etc.
Maintain the proper oil level between changes. Over¬
filling will cause foaming, which can lead to an oil leak
due to overheating. Remove the filler plug on top of
the case and the oil levei plug from the face of the gear
case. Fill the case until the oil just begins to flow from
the oil level plug hole. Gear box holds 1/2 pint US.
measure (.24 litre). Replace both plugs.
Clutch Installation: A Rockford Clutch can be in¬
stalled at the factory or In the field. Install the clutch
according to the following instructions and Figure 6.
Provide room for the clutch adapter casting by
plugging the wet holes with a 3/8-16x 1/2-inch slotted
headless set screw. Apply sealing compound to the
threads and install screw flush with the cylinder
block
hJSrVf/w f0r i h ,t £L utch set screw - L ocate center of
hole 11/32-mch (8.73 mm) from the end and directly
opposite the keyway in the crankshaft
Install the clutch adapter, with drain slot downward,
using two cap screws 3/8-16 x 2-inches on the lower
and one cap screw 3/8-16x 1-3/4-inch on the upper#2
cylinder side (cylinder nearer clutch}. Install the3/8x
3-7/8 or 4-inch stud through the adapter into the
engine block upper remaining hole. Use a lock
washer on each assembly screw. Use a flat washer
and a lock washer under the stud nut
Install the crankshaft key. Remove the dutch set
screw. Install the clutch assembly (less housing) to
the crankshaft, driving it on carefully with a soft-faced
hammer until set screw hole is aligned. Install set
11

DISCARD—- f
REPLACE WITH /
3/8-16 x \/Y* SLOTTED
HEADLESS SCREW
DISCARD
FIGURE 7. BATTERY CONNECTIONS
FIGURE 6. CLUTCH INSTALLATION
screw to bottom in crankshaft hole, then back it out
one full tum. Tighten clutch retaining screws until
dutch is clamped securely to crankshaft. Lock the
screws and tighten the set screw.
Apply grease to splined power takeoff shaft. Position
the clutch throw-out to align the grease fitting with
the hole in the housing (#1 cylinder side, horizontal).
Pull the throw-out collar outward to remove tension.
Install the clutch housing so thattheciutch throw-out
fork engages the throw-out collar. Be sure the
serrated shaft is properly meshed with the clutch
plate. Use two cap screws 7/16-14 x 2-inches on the
lower and one cap screw 7/16-14 x 1-3/4-inch on the
upper #2 cylinder side. Install the stud washer and
nut. Lubricate the two grease fittings just until grease
appears.
BATTERY CONNECTIONS (Engines with
Automotive Type Separate Starter)
Connect the 12 volt battery positive cable to the
engine start switch terminal. Connect the battery
negative cable to the ground point on the engine oil
base (Figure 7).
PROTECTION FOR EXTENDED OUT-OF¬
SERVICE PERIOD
Protect an engine that will be out-of-service for more
than 30 days as follows:
1. Run engine until thoroughly warmed up.
2. Turn off fuel supply and run until engine stops
from lack of fuel.
3. Drain oil from oil base while still warm. Attach a
warning tag to refill before operation.
4. Remove each spark plug. Pour one ounce (two
tablespoons) of rust inhibitor (orSAE#50) oil into
cylinder. Crank engine over a few times to
distribute oil film on cylinder walls and rings.
Reinstall each spark plug.
5. Service air cleaner per maintenance schedule.
6. Lubricate governor linkage. Protect against dust,
etc. by wrapping with a clean cloth.
7. Plug exhaust outlet to prevent entrance of bugs,
moisture, or dirt.
8. Wipe entire unit clean. Coat parts likely to rust
with a light film of grease or oil.
®* Provide a suitable cover for entire unit.
Disconnect battery and follow standard battery
storage procedure.
Discharged batteries are subject to
severe damage if exposed to freez¬
ing temperatures. Store all batteries in a fully charged
condition and maintain charge during storage.
12

RETURNING THE SET TO OPERATION
1. CHECK SERVICE IDENTIFICATION TAGS to
properly service the engine.
2. Uncover and remove all storage seals from
engine. Remove any dust, dirt, or foreign matter.
3. CHECK fuel supply tanks. CHECK lubricating oil
for moisture or contamination (drain if
necessary). CHECK fuel line connections, all
wiring connections, and exhaust line connec¬
tions.
4. Service air cleaner per maintenance schedule,
5. Check tag on oil base and verify that oil viscosity
is still correct for existing ambient temperature.
6. Clean and check battery. Measure specific gravity
{1.260 at 25° C [77° F]) and verify level to be at
split ring. If specific gravity is low, charge until
correct value is obtained. If level is low, add
distilled water and charge until specific gravity is
correct.DO NOT OVERCHARGE.
i WARNING | Ignition of explosive battery
u I sases might cause severe per¬
sonal infury. Do not smoke while servicing
batteries.
' ■ 7. Check engine for fuel or oil leaks. Correct leakage
as required.
8. Install fully charged batteries.
9. Start engine and check while running for leaks,
battery charge rate, and proper cooling.
After engine has started, excessive blue smoke will be exhausted
and the engine will run rough until the rust inhibitor or oil has
burned away.
WARNING \
EXHAUST GAS IS DEADLY!
Exhaust gases contain carbon monoxide, a poisonous gas that might cause
unconsciousness and death. It is an odorless and colorless gas formed during
combustion of hydrocarbon fuels. Symptoms of carbon monoxide poisoning
are:
• Dizziness • Vomiting
• Headache * Muscular Twitching
• Weakness and Sleepiness • 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 inspections of the complete exhaust system. If you notice
a change in the sound or appearance of exhaust system, shut the unit down
Immediately and have ft inspected and repaired at once by a competent
mechanic.
13

Oil System
PRESSURE LUBRICATION
These engines use an oil pump to lubricate engine
parts (Figure 8). If oil pressure is low, the pump
should be checked.
FIGURE 8. OIL SYSTEM
OIL PUMP
The oil pump (Figure 9) is mounted on the front of the
crankcase behind the gear cover and is driven by the
crankshaft gear.
A drilled passage connects the front main bearing oil
supply to the front camshaft bearing. The flyball
governor is lubricated by a drilled passage in the front
camshaft journal.
The oil overflow from the bypass valve furnishes
iubncation to the camshaft drive gears.
Norma! oil pressure should be 30 psi or higher when
the engine is at operating normal temperature. If
pressure drops below 30 psi at governed speed,
inspect the oil system for faulty components.
Check the oil pump thoroughly for worn parts. Oil the
pump to prime it before reinstalling. Except for
gaskets and suction cup, the component parts of the
pump are not available individually. Install a new
pump assembly if required.
It new oil pump gaskets are installed, they should be
the same thickness as those removed. A gasket kit
with various thickness gaskets is available.
OIL BY-PASS VALVE
The by-pass valve (located to the right and behind
gear cover, Figure 10), controls oil pressure by
allowing excess oil to flow directly back to the
crankcase. Normally the valve begins to open about
30 psi.
The valve is non-adjustable and normally needs no
maintenance. To determine if abnormal (high or low)
oil pressure is caused by a sticky plunger inspect as
follows:
1. Remove 3/8" - 24 x 3/4 inch cap screw located
behind gear cover and under governor arm.
Z Remove spring and plunger with a magnet tool.
Clean plunger and spring with a suitable solvent
and reinstall.
FIGURE a OIL PUMP ASSEMBLY
The inlet pipe and screen assembly is attached
directly to the pump body. A discharge passage in the
cover of the pump registers with a drilled passage in
the crankcase. Parallel passages distribute oil to the
front main bearing, rear main bearing and pressure
control bypass valve.
Circumferential grooves in the main bearings supply
oil to the connecting rod bearings through drilled
passages from each main journal.
Removal
To remove the valve, unscrew the recessed plug in the
rear bearing plate and lift out the spring and plunger
assembly. Determine proper valve operation by
checking the spring and plunger according to the
following measurements.
Plunger Diameter.3365" to .3380"
(8.55 to 8.59 mm)
Spring
Free Length. 2-5/16” (58.74 mm)
2.225 (1.0 kg) .11 lb. (49.9g) at 1-3/16" (30.16 mm)
14

'HEX. CAP SCREW
'FLAT WASHER
breather
HOSE
HOSE CLAMP
clamp
breather
TUBE
by-pass valve
bapfle
CRANKCASE BREATHER
Clean or replace crankcase breather baffle periodically. Be sure
baffle material doesn't come apart and work into me manifold.
FIGURE 10. OIL SYSTEM COMPONENTS
CRANKCASE BREATHER
The crankcase breather maintains a partial vacuum in
the crankcase during operation to control oil loss and
ventilate the crankcase, Figure 10.
To disassemble, remove the rubber cap from the
crankcase tube and pry the valve out of thecap. Wash
the valve in fuel at regular intervals and, if defective,
replace it. Also, pull thebaffleoutofthebreathertube
and clean it. Install the valve with the perforated disk
toward the engine.
OIL FILTER (OPTIONAL)
The full-flow filter (Figure 10) is mounted on the filter
plate at the left front comer of the crankcase. Replace
normally after every 200 hours of operation. Remove
the filter by turning counterclockwise. Lubricate the
gasket on the new filter with engine oil. install the
filter until the gasket touches the base and tighten 1/2
turn; do not overtighten.
15

Governor System
CONSTANT SPEED GOVERNOR
The standard governor is a constant speed governor.
Figure 11. A variable speed governor is shown in
Figure 12. If the following checks do not remedy
erratic governor operation, install a new governor
spring. Check the governor arm, linkage, throttle
shaft and lever for binding or excessive wear at con¬
necting points. A binding condition at any point will
cause the governor to act slowly and regulation will
be poor. Excessive looseness will cause a hunting
condition and regulation will be erratic. Work the arm
back and forth several times by hand while the engine
is shut off. Replace parts as needed.
FIGURE 11. GOVERNOR ADJUSTMENT LINKAGE
GOVERNOR ADJUSTMENTS
Where engine speed is governor controlled, the
governor is set at the factory to allow a nominal
engine speed of 2400 rpm at no-load operation
(unless another speed is specified when the engine is
ordered). Proper governor adjustment is one of the
most important factors in maintaining the power and
speed desired from the engine, Figure 11.
FIGURE 12. VARIABLE SPEED GOVERNOR
Before making governor adjustment, run the engine
about 10 minutes to reach norma! operating
temperature. Be sure carburetor main load and idle
needles are properly adjusted before checking or
adjusting governor system. For an accurate governor
adjustment, a reliable instrument, tachometer for
example, is required.
If the following checks don’t remedy erratic opera¬
tion, install a new governor spring. Springs become
fatigued with age.
Linkage
Check the governor arm, linkage, throttle shaft and
lever for a binding condition or excessive slack and
wear at connecting points. Figure 11. A binding
condition at any point will cause the governor to act
slowly and regulation will be poor. Excessive
looseness will cause a hunting condition and regula¬
tion will be erratic. Work the arm back and forth
several times by hand while the engine is idle. Replace
parts as needed.
The engine starts at wide open throttle. The length of
the linkage connecting the governor arm to the
throttle arm is adjusted by rotating the ball joint.
Adjust length so with the engine stopped and tension
on the governor spring, the carburetor throttle lever is
wide open. This setting allows immediate control by
the governor after starting and synchronizes travel of
the governor arm and the throttle shaft.
The adjustable governors use the same procedure for sensitivity
adjustment but the speed adjustment for the variable speed
governor {Figure 13) is different If engine has variable speed
governor as shown, proceed to Variable Speed Governor Adjust¬
ment.
16

The linkage must be able to move freely through Its
entire travel. Beginning Spec J, clean and lubricate
steel ball joints using a drop of light oil or graphite.
Earlier models used plastic ball joints which require
no lubrication. See Figure 12a.
lubricate with graphite.
FIGURE 12a. GOVERNOR LINKAGE
Sensitivity Adjustment
The engine speed drop from no-load to full-ioad must
be within 100 rpm. Check the engine speed with no
load connected and again after connecting a full-
rated load.
The sensitivity of the governor depends upon the
position of the arm end of the governor spring. A
series of holes in the governor arm provides for
adjustment. To increase sensitivity, move the gover¬
nor spring toward the governor shaft. To decrease
sensitivity, move the governor spring toward the link¬
age end of the governor arm.
A too-sensitive setting will result in a surging speed (hunting)
condition, an alternate increase and decrease in engine speed. An
opposite setting will result in too much speed variation between
no-load and full-load conditions.
Always recheck the speed adjustment after a sensitiv¬
ity adjustment. Increasing sensitivity will cause a
slight decrease in speed and will require a slight
increase in the governor spring tension.
Constant Speed Governor Adjustment
The speed at which the engine operates is deter¬
mined by the tension applied to the governor spring.
Increasing spring tension increases engine speed.
Decreasing spring tension decreases engine speed.
The no-load speed of the engine should be slightly
higherthan the speed requirementsofthe connected
load. For example, if the connected load is to turn at
2310 rpm, set the no-load speed of the engine at
about 2400 rpm. Check speed with a tachometer. If a
speed adjustment is needed, turn the speed adjusting
nut in to increase the speed or out to decrease the
speed {Figures 11 and 12).
Variable Speed Governor
Adjustment
These governors are adapted for use where a wide
range of speed settings is desired. Engine speed is
controlled at any given point between minimum and
maximum by simply shifting the speed control lever
until the desired speed is reached.
The adjustable governors use the same procedure for sensitivity
adjustment, but the speed adjustment for the variable speed gov¬
ernor (Figure 13) is different
The design of the variable speed governor gives an
automatic decrease in sensitivity when the speed is
increased and the result is good stability at all speeds.
Adjust the governor as follows:
1. Make sure carburetor is adjusted correctly {see
FUEL SYSTEM section).
2. Adjust the throttle stop screw on the carburetor to
a minimum idling speed of 1,450 rpm so the gov¬
ernor spring can hold the engine at 1,500 rpm. (A
lower minimum does not assure smooth opera¬
tion under load.)
3. Adjust governor spring tension for minimum
speed. Shift the lever to the minimum (slow) posi¬
tion and with no-load connected, adjust the
spring tension for about 1,500 rpm.
4. Adjust the sensitivity while operating at minimum
speed to attain the smoothest no-load to full-load
operation as follows:
To decrease sensitivity {allow more speed drop
from no-load to full-load operation): Move the
governor spring outwards into a different groove
or hole in the extension (or on earlier models, turn
the sensitivity screw outwards) so that the point
of puli by the spring is moved slightly farther from
the governor shaft.
To increase sensitivity (closer regulation by the
governor which permits less speed drop from no-
load to full-load operation): Move the governor
spring inward into a different groove or hole in the
extension (or on earlier models, turn the sensitiv¬
ity screw inward) so that the point of puli by
spring is moved slightly closer to the governor
shaft.
5. A pply a full-load and shift the speed control lever
until the engine speed reaches the desired maxi¬
mum speed. Set the screw in the bracket slot to
stop lever travel at the desired maximum full-load
speed position. A full-load speed of 3600 rpm is
the recommended maximum for continuous
operation. The speed must agree with the load
requirements.
17

Two-Speed Governor (Electric Solenoid Type)
Low speed is controlled by the Jow-speed governor
spring. High speed is controlled by both governor
springs {low-speed and high-speed spring).
To adjust the two-speed governor, follow the steps as
outlined below, and refer to Figure 13a.
1. Run the engine and make necessary carburetor
adjustment.
2. Adjust low-speed tension for the desired low
speed (recommended minimum idling speed of
1,500 rpm for engines operating under load at idie
speed). Decreasing spring tension decreases
enginespeed. Increasing spring tension increases
engine speed.
3. Adjust high-speed tension by turning the plunger
on the adjusting stud (with locking nut loosened)
so when the plunger is pulled all the way into the
solenoid it gives the desired high speed. Approx¬
imately 3,000 rpm is the recommended maximum
full load speed for continuous operation.
Extreme tension on the high
speedgovemorspringvfiltcause
damage to the solenoid colt Tension must be
loose enough so that the plunger will pull all the
way into solenoid when operating at high speed.
Failure to do so will not open the contact points
within the solenoid, which will cause the coll to
overheat
4. Adjust the sensitivity for high-speed operation to
attain the smoothest no-load operation.
To decrease sensitivity (allow more speed drop
from no-load to full-load operation): Move the
high-speed governor spring outward into a dif¬
ferent hole in the bracket so that the point of pull
by the spring is moved slightly farther from the
governor shaft.
To increase sensitivity (closer regulation by the
governor which permits less speed drop from no-
load to full-load operation): Move the high-speed
governor spring inward intoadifferent hole of the
bracket so that the point of pull by the spring is
moved slightly closer to the governor shaft.
SOLENOID
CARBURETOR
THROTTLE THROTTLE PLATEf
-T» I
BRACKET
HIGH SPEED
GOVERNOR SPRING
THIS DISTANCE
DETERMINES SENSITIVITY
GOVERNOR ARM
AND SHAFT
GOVERNOR CUP
GOVERNOR SHAFT
YOKE
FIGURE 13*. ELECTRIC GOVERNOR
The low-speed governor spring normally requires
no sensitivity adjustment and can be moved to
another hole in the bracket to allow proper
adjustment of the high-speed sensitivity. If sensi¬
tivity adjustment is required for low speed, move
the low speed spring in the same manner as
instructed for the high-speed spring.
18