Onan CCKB User manual

Onon
Operator’s
Manual
OCCCB
GenSet
927-0123
9-78 (Spec E)
Printad in

Safety Precautions
Before operating the generator set, read the Operator’s
Manual and become familiar with it and the equipment. Safe
and efficient operation can be achieved only if the unit is
properly operated and maintained. Many accidents are
caused by failure to follow fundamental rules and precautions.
The following symbols, found throughout this manual, alert you
to potentially dangerous conditions to the operator, service per¬
sonnel, or the equipment.
ADANGER
This symbol warns of immediate haz¬
ards which will result in severe personal injury or
death.
^W ARNING This symbol refers to a hazard or unsafe
practice which can result in severe personal injury
or death.
• Do not wear loose clothing or jewelry while servicing any
part of the generator set. Loose clothing and jewelry can
become caught in moving parts. Jewelry can short out
electrical contacts and cause shock or burning.
• If adjustment must be made while the unit is running, use
extreme caution around hot manifolds, moving parts, etc.
ELECTRICAL SHOCK WILL CAUSE SEVERE
PERSONAL INJURY OR DEATH
• Remove electric power before removing protective shields
or touching electrical equipment. Use rubber Insulative
mats placed on dry wood platforms over floors that are
metal or concrete when around electrical equipment. Do
not wear damp clothing (particularly wet shoes) or allow
skin surfaces to be dampKwhen handling electrical equip¬
ment.
^CAOjibN’ This symbol refers to a hazard or unsafe
practice which can result in personal Injury or prod¬
uct or property damage.
FUEL AND FUMES ARE FLAMMABLE. Fire, explosion, and
personal injury can result from improper practices.
• DO NOT fill fuel tanks with the engine running unless tanks
are outside the engine compartment. Fuel contact with hot
engine or exhaust is a potential fire hazard.
• DO NOT SMOKE OR ALLOW AN OPEN FLAME near the
generator set or fuel tank. Internal combustion engine fu¬
els are highly flammable.
• Fuel lines must be adequately secured and free of leaks.
Fuel connections at the engine should be made with an ap¬
proved flexible line. Do not use copper piping on flexible
lines as copper will work harden arid become brittle.
• Be sure that ail fuel supplies have a positive shutoff valve.
• DO NOT SMOKE while servicing batteries. Lead acid bat¬
teries emit a highly explosive hydrogen gas that can be ig¬
nited by electrical arcing or by smoking.
EXHAUST GASES ARE DEADLY
• Provide an adequate exhaust system to properly expel dis¬
charged gases. Inspect the exhaust system daily for leaks
per the maintenance schedule. See that exhaust mani¬
folds are secure and are not warped. Do not use exhaust
gases to heat a compartment.
• Be sure the unit is well ventilated.
MOVING PARTS CAN CAUSE SEVERE PERSONAL
INJURY OR DEATH
• Keep your hands away from moving parts.
• Before performIng any maintenance on the generator set,
disconnect the starting battery negative (—) ground lead
lead first. This will prevent accidental starting.
• Make sure that fasteners on the generator set are secure.
Tighten supports and clamps, keep guards in position over
fans, drive belts, etc.
• Use extreme caution when working on electrical compo¬
nents. High voltages can cause injury or death. DO NOT
tamper with interlocks.
• Follow all state and local electrical codes. Have ail electri¬
cal installations performed by a qualified licensed electri¬
cian. Tag open switches to avoid accidental closure.
• DO NOT CONNECTTHE GENERATOR SET DIRECTLY
TO ANY BUILDING ELECTRICAL POWER SYSTEM.
Hazardous voltages can flow from the generator set into
the utility line. This creates a potential for electrocution or
property damage. Connect only through an approved de¬
vice and after building main switch is open. Consult an
electrician in regard to emergency power use.
GENERAL SAFETY PRECAUTIONS
• Provide appropriate fire extinguishers and install them in
convenient locations. Consult your local fire department
for the correct type of extinguisher to use. Do not use foam
on electrical fires. Use extinguisher rated ABC by NFPA.
• Used engine oils have been identified by some state or fed¬
eral agencies as causing cancer or reproductive toxicity.
When checking or changing engine oil, take care not to in¬
gest, breathe the fumes, or contact used oil.
• Benzene and lead, found in some gasoline, have been
identified by some state and federal agencies as causing
cancer or reproductive toxicity. When checking, draining
or adding gasoline, take care not to ingest, breathe the
fumes, or contact gasoline.
• Make sure that rags are not left on or near the engine.
• Remove ail unnecessary grease and oil from the unit. Ac¬
cumulated grease and oil can cause over heating and en¬
gine damage, and present a potential fire hazard.
• Keep the generator set and the surrounding area clean
and free from obstructions. Remove any debris from the
set and keep the floor clean and dry.
• Do not work on this equipment when mentally or physically
fatigued, or after consuming any alcohol or drug that
makes the operation of equipment unsafe.
SS-7

GENERAL INFORMATION
YOUR MANUAL
This manual contains installation, operation, and
other information to properly maintain, service, and
make adjustments on your CCKB generating set.
Study and follo\w the instructions carefully. A well-
planned service and maintenance program will result
in longer unit life and better performance. Because
ihe most important part of repair is diagnosis, a
troubleshooting guide is included.
MODEL DESIGNATION
The following typical model number is broken down
into code segments:
10.0 CCKB
1 2
3C R / 1 E
TI IT
3 4 5 6
throughout the manual, engine end of the generating
;t is the front. Left and right sides are determined
'.'her. facing the engine (front) end.
vVhen contacting yourOnan dealer, distributor, orthe
factory about the generating set, always supply the
complete model number and serial number as shown
on the nameplate (see Model Designation following).
This information is necessary to identify your
generating set among the many types manufactured
by Onan.
Where applicable, metric equivalents appear in parentheses follow-
ing the U S. customary units.
1. Indicates kilowatt rating.
2. Series identification.
3. Voltage code of the generator.
3 - 120/240 volts
C = Reconnectible feature
4. Method of starting:
R - remote electric starting
P - portable unit with manual starting, and
E - electric starting.
5. Factory code for designating optional equipment,
if any.
6. Specification letter which advances when the
factory makes production modifications.
TABLE OF CONTENTS
General Information. 1
Specifications. 2
Description. 3
Installation. 4
Operation. 9
Adjustments.12
Service and Maintenance.16
Troubleshooting Guide.19
Parts Information.20
WARNING
TO AVOID POSSIBLE PERSONAL INJURY OR
EQUIPMENT DAMAGE, A QUALIFIED ELECTRI¬
CIAN OR AN AUTHORIZED SERVICE
REPRESENTATIVE MUST PERFORM IN¬
STALLATION AND ALL SERVICE.
1

SPECIFICATIONS
ENGINE DETAILS
Number of Cylinders (horizontally opposed) ...
Cylinder Bore.
Piston Stroke.
Displacement (cubic inch) .
Compression Ratio.
Power Output (3600 r/min).
Engine Speed.
Fuel Pump.
IGNITION TYPE
Portable (Manual Start).
Remote Start (Electric Crank).
STARTING
Portable.
Remote Start.
Battery Voltage (Two 6 Volt Batteries in Series)
Capacity Recommendation.
Battery Charge Rate (fixed 2-step).
CAPACITIES AND REQUIREMENTS
Oil Capacity.
Generator Cooling Air (at 3600 r/min).
Engine Cooling Air (at 3600 r/min).
Combustion Air (at 3600 r/min).
Total Air Required.
GENERATOR DETAILS*
Design.
Power Factor.
. 2
. 3.25 inches (82.55 mm)
. 3 inches (76.20 mm)
. 49.8 inches (816.22 cm^)
. 7.0:1
. 19.5 BMP (14.5 kW)
. 3600 r/min
. Diaphragm, 4 ft lift (1.2 m)
. Flywheel Magneto
. Battery
. Manual Pull Rope (Recoil)
. Exciter Cranking (Gen)
. 12V
. 105 a/hr (378 kC)
. 1-3 a
. 4 U.S. quarts (3.8 litre)
. 150 CFM (.07 mVsec)
. 900 CFM (0.42 mVsec)
. 42 CFM (0.02 mVsec)
. 1092 CFM (0.51 mVsec)
2 pole, revolving armature, self-exciter
. 1.0
TUNE-UP SPECIFICATIONS
Breaker Point Gap (Full Separation) ..
Spark Plug Gap
Gasoline Fuel .
Gaseous Fuel .
Ignition Timing
Engine Running.
Static Setting.
Carburetor Float Level (Zenith).
Early Models (Carter).
Valve Tappet Clearance (Engine Cold)
Intake.
Exhaust.
Compression (at cranking speed).
Cylinder Head Torque.
. 0.020 inch (.51 mm)
. 0.025 inch (.64 mm)
. 0.018 inch (.46 mm)
. 24° BTC
1°ATC (Manual Start), 24° BTC (Electric Start)
. 1/8 inch (3.18 mm)
. 11/64 inch (4.37 mm)
. 0.006 inch - 0.008 inch (0.15 mm - 0.20 mm)
. 0.015 inch - 0.017 inch (0.38 mm - 0.43 mm)
. 100 - 120 PSI(48 - 52 kPa)
. 29 - 31 ft lb (39 - 42 N*m)
* - See nameplate for generator current ratings.
2

DESCRIPTION
GENERAL
An Onan CCKB Series electric generating set con¬
sists of a two-cylinder gasoline engine and an alter¬
nating current generator with standard or optional
equipment as ordered.
ENGINE
The CCKB engine has 49.8 cubic inch (816 cm^)
piston displacement, 7.0 to 1 compression ratio, and
is air-cooled. Basic measurements and other details
are listed under SPECIFICATIONS.
GENERATOR
The generator is a revolving armature, 2-pole, single
phase, self-excited model of drip-proof construction.
PORTABLE
The generator aligns to the engine through a rigid
coupling. A commutator, collector rings and
associated brushes provide the electrical connec¬
tions.
CONTROLS
The control box has a START-STOP switch. The
portable model has a six receptacle outlet box with a
pilot light. The following is a brief description of
typical controls.
Start-Stop Switch: Starts and stops the unit locally.
Oil Pressure Gauge: Indicates pressure of lubricating
oil in engine (located on the engine).
GAUGE
REMOTE START
TYPICAL CCKB MODELS
3

INSTALLATION
GENERAL
Installations must be considered individually,
however, the following installation guidelines should
be followed. Installations must conform to local
building codes, fire ordinances and other local, state
or federal regulations. See Figure 1.
installation points to consider include:
1 Level mounting surface.
2 Adequate cooling air.
3. Adequate fresh induction air.
4. Discharge of circulated air.
5 Discharge of exhaust gases.
6 Eiectncai connections.
7 -ut-! connections.
8 Accessibility for operation and servicing.
9 Vibration isolation.
10 N o i s e levels.
Provide a location that is protected from the weather
and IS dry. clean, dust free and well ventilated. If
practical, install inside a heated building for protec-
tio*^ from extremes in weather conditions.
Permanent installations need a sturdy, level mounting
base of concrete, heavy wood, structural steel or
other sturdy support at least 12 inches (305 mm) high
to aid routine maintenance, operation and service.
Assemble the vibration isolators in the order as shown
in Figure 2. The spacer bushing prevents compres¬
sion of the snubber or upper rubber cushion. Two
CARRIAGE BOLT
SQUARE NUT
LOCK WASHER
FLAT WASHER
SNUBBER
GENERATOR OR
OIL BASE MOUNTING
FOOT
CUSHION
MOUNTING SPACER
BUSHING
FLAT WASHER
The aif discharge side of set requires 3 inches
(76 mm) clearance from wall to permit set to rock on
Its mounts; at least 24 inches (610 mm) clearance is
required around all other sides for service accessibili-
FIGURE 2. VIBRATION ISOLATOR
FIGURE 1. TYPICAL CCKB GENERATING SET INSTALLATION
4

vibration isolators are for the engine end only and the
other two are for the generator end only. Use them for
their respective positions or undesirable cushioning
will result.
BATTERY CONNECTION
VENTILATION AND COOLING
Ventilation and cooling for outdoor installations
usually present no problems. Indoor installations,
however, require properly sized and located vents for
both inlet and outlet air. See Specifications section
for required airflow. The outlet should be slightly
higher than the inlet for convection airflow.
F^ovuie two 6 volt batteries connected in series
F ' 1 i !of a 12 volt source. See Specifications tor
n-irarnum battery ampere-hour rating.
Connect the battery positive (+) cable to the start
solenoid (located in the control box). Route the
battery cable through the rear of the control box.
Connect the battery negative (-) to a good ground on
the generator set frame. See Figures 1 and 3.
Do not disconnect starting batteries while set
is running. The resulting overvoltage condi¬
tion will damage electric choke and may damage control com¬
ponents.
Standby installations: If the installation is forstandby
service, install a double-throw transfer switch (either
manual or automatic) to prevent feeding generator
output into the normal power source lines and to also
preventcommercial powerand generator output from
being connected to the load at the same time.
GROUNDING
WARNING I prsvent shock hazard, ground the set.
Connect a #8 or larger wire between: (1) a
separate ground pipe or rod penetrating into moist earth; (2) and
the solderless connector located on the generator (on models not
so equipped, to the battery ground stud on the engine). See Figure
3.
The required amount of air must reach the unit,
absorb the heat and be discharged away from the
installation area. When determining vent sizes, con¬
sider the following:
1. Size of enclosure.
2. Ambient temperature.
3. Electrical load.
4. Running time.
5. Restrictions — screens, filters, etc.
6. Prevailing wind direction.
If the generating set is enclosed in a small, poorly
ventilated enclosure, auxiliary fans can be used to
increase airflow. The air inlet to the engine must not
exceed 120° F (49°C) when running atfullload. If inlet
air is more than 10°F (12°C) above ambient air, there
is a good possibility that cooling air is recirculating.
Pressure Cooling: These units need an inlet vent with
an unrestricted opening of 2-1/2 square feet (2.3 m^).
Install a separate duct from the engine for the
discharge air.
The discharge duct must be at least as large as the
inlet vent. If a screen is used in the duct, increase the
duct size proportionately to the screen restriction.
Use large radius elbows for bends and increase the
duct size for runs overSfeet (1.5 m). A canvas section
in the duct prevents transmission of vibration. A slight
pitch upward in the duct lets heat escape when the
unit is stopped and minimizes vapor lock.
Do not use discharged air for heating since it
may contain poisonous gases.
warningI
FIGURE 3. BATTERY AND GROUND CONNECTIONS
s

FUEL
Fuel Connection (Gasoline): For gasoline-fueled
generating sets, other than the contractor and por¬
table models which have their own fuel tank, connect
a fuel line to the fuel pump inlet, which is threaded
1/8-inch NPTF (National Pipe Thread Female). Use a
flexible line next to the unitto prevent transmission of
vibration to the fuel line.
Fuel Connection (Gaseous): For gaseous-fueled
generating sets, check with your local supplierforgas
and pressure regulations. See Figure 4. Provide a
manual gas shutoff. A filter in the line may also be
necessary. Electric solenoid shutoff valves are usual¬
ly required for indoor automatic or remote starting
installations. Connect the solenoid wires to the
battery circuit to open the valve while the unit is
running. Also install a demand-type regulator and
locate It near the generating set to aid starting
(regular line pressure must be within 2 to 8 ounces 157
to 227 g]).
An auxiliary reservoir fuel tank is often used for
standby installations. For these installations, the fuel
line connections must be changed as shown in Figure
VENT CAP
(Install at least 3 feet
above reservoir tank)
5/16’* VENT LINE
TO EXTERIOR OF BUILDING
- V
RESERVOIR TANK
(Mount above carburetor
bowl level)
5/16” FUEL LINE
FROM FUEL PUMP
5/16” LINE TO
ENGINE CARBURETORl
^3/8” RETURN LINE
TO MAIN FUEL TANK
J
Always use flexible tubing between engine and gas demand
regulator to absorb vibration.
FIGURE 5. AUXILIARY RESERVOIR FUEL TANK
Gasoline Tank: If a separate fuel tank is used, install
the tank so its bottom is less than 4 feet (1.2 m) below
the fuel pump. The tank top must also be below the
fuel pump level to preventsiphoning. If thefuel tank is
shared with another engine, use a separate fuel line.
If the fuel must be listed overfourfeet (1.2 m), install
an auxiliary electric fuel pump at the fuel supply.
j WARNING^ In most vehicle applications since August,
1972, the vehicle uses an Evaporative Emis¬
sion Control System. These systems may become pressurized if the
normal venting system becomes plugged. If this occurs when the
generating set is not running and especially If vehicle is moving,
gasoline can be forced through the carburetor, flooding the
generator set. For this reason a separate manual or electrical fuel
shut-off MUST be provided in thefuel line between the supply tank
and the generator set fuel pump inlet to prevent flooding the
generator set when not in use.
A776
^ PIPE PLUG
[1— N I P P L E
90® ELBOW
REDUCING BUSHING
coptional>
DEMAND-TYPE
GAS REGULATOR
ADJUSTING SCREW
.VENT
/TO CONVENIENT GROUND
ON GENERATING SET
TO CONTROL TERMINAL F S
ELECTRIC SOLENOID '
SHUT OFF VALVE
manual
SHUT OFF
,/
7^ 4 gas SUPPLY LINE
— DRY FUEL
filter
FIGURE 4. CONNECTIONS FOR GAS LINE TO CCKB
6

EXHAUST
Vent all exhaust gases outside. The exhaust outlet
must not terminate near air inlet vents or combustible
materials. Avoid sharp bends and use large radius
elbows in the exhaust piping. If the piping cannot be
pitched downward, install a condensation trap in the
system where a rise begins (Figure 6). The exhaust
line connects to a one-inch NPTF outlet at engine.
Use one pipe size larger for each ten feet in length.
Position the exhaust outlet away from the set air
intake.
WARNING I POISONOUS exhaust gas outside
enclosure. Inhalation of exhaust gases can
result in serious injury or death.
IF EXHAUST LINE MUST BE PITCHED
UPWARD CONSTRUCT A TRAP OF PIPE
FITTINGS AT POINT OF RISE
[
AVOID SHARP BENDS
DRAIN CONDENSATION TRAP
PERIODICALLY
FIGURE 6. CONDENSATION TRAP
Exhaust piping must not come closer than 9 inches to
combustible material. Where the system leaves the
building, install a thimble. See Figure 7.
SINGLE THIMBLE DIAMETER 12
LARGER OR DOUBLE
^ VENTILATED THIMBLE
DIAMETER 6 LARGER
THAN EXHAUST LINE
HOLES IN END
INNER SLEEVE
EXHAUST LINE PASSING THROUGH
It WALL OR PARTITION
FIGURE 7. EXHAUST THIMBLE
OIL DRAIN
If desired for convenience in draining oil, remove the
oil drain plug and install an extension pipe and
coupling. Oil base has 3/8-inch pipe tapped hole.
REMOTE START-STOP SWITCH (Optional)
For remote control starting and stopping, use three
wires to connect the remote switch (SPOT, momen¬
tary contact, center-off type) to the terminal block
marked B+, 1, 2, 3, in the set control box. Use #18
gauge wire for runs up to 250 feet (76 m) and larger
wire for longer runs. See Figure 8.
LOAD WIRE CONNECTIONS
The generating set nameplate shows the electrical
output rating of the set in watts, volts and hertz. The
portable models are prewired and have a receptacle
box with two duplex 120-volt (15-ampere), grounding
receptacles and two 240-volt (20-ampere), twist-lock
receptacles. For the other generating sets, the wiring
diagram shows the electrical circuits and necessary
connections for the available output voltage.
A qualified serviceman orelectrician should make the
installation and the installation should be inspected
and approved to meet all applicable code re¬
quirements. The AC output box has provisions to
accommodate load wires. Use flexible conduit and
sufficiently large stranded load wires near the set to
absorb vibration. Strip the insulation from the wire
ends as necessary for clean connections. Connect
each load wire to the proper generator output lead
inside the AC output box. Insulate bare ends of
ungrounded wires. Install a fused main switch (or
circuit breaker) between the generating set and the
load.
Reconnectible, Single-Phase Generator: Voltage
selection on reconnectible sing ie-phase generators is
120/240 volts, 3 wire; 120 volts, 2 wire; or, 240 volts, 2
wire (Figure 9). Use the connection for two-wire
service when one load exceeds one-half the rated
capacity. Balance the load when connecting for
three-wire service. Current for any one output lead
must not exceed nameplate rating. Serious
overloading can damage the generator windings.
When two or more single-phasecircuitsareavailable,
divide the load equally between them.
Three-Phase, Four-Wire, Wye Connected
Generators: A three-phase, four-wire generating set
produces single-phase current of the lower
nameplate voltage and three-phase current of the
higher nameplate voltage (Figure 10). For single¬
phase current, connect the neutral (white) load wire
to the grounded terminal. Connect the “hot”
(black) load wire to any one of the other three
terminals . . . M', or M^. Three separate single¬
phase circuits are available, with not more than one-
third the rated capacity of the generating set from any
one circuit. For three-phase current, connect
separate load wires to eachofthegeneratorterminals
M\ and M^. Single-phase current of the higher
nameplate voltage is obtained between any two three-
phase terminals.
FIGURE 8. REMOTE START-STOP SWITCH
7

120 VOLT. 2 WIRE
240 VOLT. 2 WIRE
FIGURE 9. SINGLE PHASE, 3CR GENERATOR CONNECTIONS
A
B
3-PHASE
HIGHER
NAMEPLATE
VOLTAGE
Ml
M2
M3
- Lower nameplate voltage, I phase circuit.
- Higher nameplate voltage, I phase circuit.
FIGURE 10. THREE PHASE WYE GENERATOR CONNECTIONS FOR VOLTAGE CODES -4 AND -4X.
8
GENER^ATOR
LEADS

OPERATION
INITIAL START
Check the engine to make sure it has been filled with
oil and fuel. If engine fails to start at first attempt,
inhibitor oil used at the factory may have fouled the
spark plugs — remove, clean in a suitable solvent, dry
thoroughly and install. Heavy exhaust smoke when
the engine is first started is normal and is caused by
the inhibitor oil.
Recommended Fuel: For new engines, most satisfac¬
tory results are obtained by using nonleaded gas¬
oline. For older engines that have previously used
leaded gasoline, heads must betaken off and all lead
deposits removed from engine before switching to
nonleaded gasoline. Do not use highly leaded
premium fuels.
! Never fill the tank when the engine is running
and leave some fuel expansion space to
prevent possibility of explosion.
Crankcase Oil: Use a good quality, heavy duty oil with
the API (American Petroleum Institute) designation
SE or S^CC (gasoline operation only). If this oil is
not available, SD or SD/CC designated oil can be
used. For gaseous fuel operation, use an ashless or
low-ash detergent oil specifically made for gaseous
fueled engines.
If lead deposits are not removed from engine
before switching from leaded to nonleaded
gasoline, pre-ignition could occur causing severe damage to the
engine.
ELECTRIC STARTING
Remote Control, AC Set: Push thesfarf-sfop switch to
its start position. Release the switch as soon as the set
starts.
Oil consumption may be higher with a multigrade oil
than with a single-grade oil if both oils have com,-
parable viscosities at 210° F (99°C). Therefore, single
grade oils are generally more desirable unless an¬
ticipating a wide range of temperatures. Use the
proper grade oil for the expected conditions (Chart
1 ) .
MANUAL STARTING
Portable Type Set: Close the manual choke about
three-quarters or as necessary according to
temperature conditions. Pull the start rope with a fast,
steady pull to crank the engine. Do not jerk. Asthe set
warms up, adjust the choke gradually to its fully open
position.
CHART 1. OIL RECOMMENDATIONS ACCORDING TO
AIR TEMPERATURE
Above 32°F (0°C).SAE 30
0°F to 32°F (0°C).SAE 10W-40 or 5W-30
Below 0°F (-18°C) .SAE 5W-30
APPLYING LOAD
Allow set to warm up before connecting a heavy load
and keep the load within nameplate rating. Con¬
tinuous generator overloading may cause high
operating temperatures that can damage the win¬
dings.
BATTERY CHARGING
The battery charge rate is controlled by a two-step
charge regulator. This regulator is preset and is not
adjustable.
Do not mix brands or grades. Refer to Maintenance
section for recommended oil changes.
9

SAFETY DEVICES (Optional)
A high air temperature switch can be installed in the
cooling system that stops the set if the engine
overheats.
If the engine has a low oil pressure switch, the switch
will stop the set whenever the oil pressure drops
below a safe operating pressure. After such a stop,
investigate and correct the cause.
BREAK-IN PROCEDURE
A reconditioned unit should be run in the following
sequence using SEorSE/CCoil (seeoil requirements
for correct viscosity). New units have been run under
load at the factory.
1. One half hour at half load.
2. One half hour at three quarter load.
3. Full load for several hours, if possible.
This method of load application speeds piston ring
seating Continuous running at half (or lighter) load
for the first few hundred hours usually results in poor
piston ring seating, causing higher than normal oil
consumption and blow-by.
STARTING SEQUENCE
1. Operator pushes START switch or set is started
by remote control.
2. Start solenoid energizes.
3. Battery current flow to:
a) series field
b) STOP relay
c) electric choke
4 Ignition coil fires spark plugs when breaker points
open.
5. Engine starts
6 Operator releases START switch
7. Start-disconnect relay energizes
8. Engine continues running.
STOPPING SEQUENCE
1. Operator pushes STOP switch
2. Stop relay opens ignition circuit
3. Engine stops
4. Operator releases STOP switch.
GENERATING SET EXERCISE
Infrequent use results in hard starting. Operate
generating set one 30-minute period each week. Run
longer if battery needs charging, or keep battery
charged with a separate charger. Exercising for one
long period each week is better than several short
periods.
GAS-GASOLINE CONVERSION
Engines having a combination gas-gasoline car¬
buretor can be switched to gasoline operation by the
following procedure:
1. Close the gaseous fuel shutoff valve in supply
line, wherever located.
2. Open the gasoline fuel shutoff valve, wherever
located.
3. Set the spark plug gap as given in the
Specifications section.
4. See that the choke is free and works easily (be
sure to release choke lock on units with electric
choke).
5. Start the engine. If the engine runs unevenly
under half or full load, the carburetor main jet
probably needs adjusting. This is not the same
main adjusting screw as that used for gaseous
fuel. Another adjusting screw is provided for this
purpose (refer to Adjustments section).
To change back to gaseous fuel operation, reverse the above
procedure.
HIGH TEMPERATURE OPERATION TIPS
1. See that nothing obstructs air flow to-and-from
the set.
2. Keep cooling system clean.
3. Keep ignition timing properly adjusted.
4. Use correct oil grade (heavier).
LOW TEMPERATURE OPERATION TIPS
1. Use correct SAE No. oil for temperature con¬
ditions. Change oil only when engine is warm. If
an unexpected temperature drop causes an
emergency, move the set to a warm location or
apply heated air (never use open flame) externally
until oil flows freely.
2. Use fresh non leaded or regular grade (not
P^erri/um) gasoline. Protect against moisture con¬
densation. Below 0° F (-18° C) adjust carburetor
main jet for slightly richer fuel mixture.
3. Keep ignition system clean, properly adjusted,
and batteries in a well charged condition.
4. Partially restrict cool airflow but use care to avoid
overheating.
HIGH ALTITUDE
For operation at altitudes of 2500 feet (762 m) above
sea level, close carburetor main jet adjustment slight¬
ly to maintain proper air-to-fuel ratio (refer to
Adjustments section). Maximum power will be reduc¬
ed approximately 4 percent for each 1000 feet (305 m)
above sea level, after the first 1000 feet (305 m).
10

DUST AND DIRT
Keep set clean. Keep cooling system clean.
2. Service air cleaner as frequently as necessary.
3. Change crankcase oil every 100 operating hours.
4. Keep oil and gasoline in dust-tight containers.
5. Keep governor linkage clean.
6. Clean generator brushes, slip rings and com¬
mutator — do not remove normal (dark brown)
film. Do not polish.
EXTENDED OUT-OF-SERVICE PROTEC¬
TION
Generator sets removed from service for extended
periods of time (over 30 days) should be protected
from rust and corrosion. Onan recommends the
following protective procedure:
1. Run set until thoroughly warm with generator
under at least 50 percent load. Stop engine by
shutting off fuel supply to allow engine to drain
fuel lines and carburetor.
2. Drain oil base while still warm. Refill and attach a
tag indicating viscosity of oil used.
3. Remove spark plugs. Pour 1-ounce of rust in¬
hibiting oil (or SAE #10 oil) into each cylinder.
Crank engine over several times, install spark
plugs.
4. Service air cleaner.
5. Clean throttle and governor linkage; protect by
wrapping with a clean cloth.
6. Plug exhaust outlets to prevent entrance of
moisture, bugs, dirt, etc.
7. Clean off dirt and dry entire unit. Coat parts likely
to rust with a light film of oil or grease.
8. Disconnect battery and follow standard battery
storage procedure. Apply a film of non-
conductive grease (e.g., vaseline) to battery cable
terminal lugs.
9. Fill fuel tank to prevent condensate contamina¬
tion.
10. P r ovide a suitable protective cover for the entire
unit.
WARNING If smoke while servicing batteries.
Explosive gases are emitted from
batteries in operation. Ignition of these gases can cause
severe personal injury.
4. Connect batteries.
5. Verify that no loads are connected to the
generator.
6. Start engine.
After engine has started, excessive blue smoke will be
exhausted and the engine wili run rough untii the rust inhibitor
or oil has burned away.
7. After start, apply load to at least 50 percent of
rated capacity.
8 Check all gauges for correct reading. Unit is
ready for service.
RETURNING UNIT TO SERVICE
1. Remove cover and all protective wrapping.
Remove plug from exhaust outlet.
2. Check tag on oil base and verify that oil viscosity
is still correct for existing ambient temperature.
3. 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.
11

ADJUSTMENTS
BREAKER POINTS - TIMING
For best engine performance, it is essential that the
breaker point gap and the ignition timing are correctly
set. Timing should always be checked when the
breaker points are adjusted or replaced. Always
replace breaker points that are burned or pitted.
Breaker Points
To check the breaker point gap, remove the breaker
box cover and crank the engine slowly by hand in the
direction of crankshaft rotation (clockwise as viewed
from engine front) until the points just start to open.
Continue turning until the points are fully separated
(about 1/4 turn). Using a clean, flat thickness gauge,
check for a proper separation of .020 inch (0.51 mm).
To adjust the gap (Figure 11), loosen locking screws
(A) and turn the off-center screw (B) until separation
is correct. Retighten the locking screws (A) and
recheck gap.
FOR MODELS WITH BREAKER BOX
FACING REAR OF ENGINE
^ -ADVANCE SPARK
retard spark-
PLACE A DROP OF
LIGHT OIL ON
BREAKER ARM PIVOT
SHAFT EVERY 200
OPERATING HOURS
To adjust gap
loosen screws A
turn cam B.
SET BREAKER POINT
GAP AT 0.020 '' (0.51 mm)
LOOSEN THE SCREWS
TO ADJUST POSITION OF
BREAKER BOX
REFERENCE MARK
FIGURE 11. BREAKER POINTS
Timing
The ignition timing marks can normally be viewed
through the blower housing on thef ront of the engine.
Align the timing mark stamped on the flywheel with
the marks stamped on the gear cover (Figure 12). If
more than one mark is stamped on the flywheel, align
the TC mark on the flywheel with the gear cover
marks. Engines equipped with Vacu-flo cooling have
a removable dot button on the blower housing for
viewing timing marks (Figure 13).
To check the ignition timing with the engine not
running, connect a continuity tester across the
breaker points. Turn the engine against crankshaft
rotation (counterclockwise as viewed from engine
front) until the points close (tester shows continuity).
Then slowly turn the engine with rotation until
continuity just ceases (points are just opening). At
this setting, the timing pointer should align with the
correct timing mark.
To check the ignition timing with the engine running,
connect an automotive timing light to either spark
plug and start the engine. With the engine running at
rated speed, the timing mark on the flywheel should
align with the correct timing mark on the gear cover.
To change the timing setting, loosen the two breaker
box mounting screws and slide the breaker box
assembly to advance or retard the ignition spark
(Figure 11).
CARBURETOR ADJUSTMENTS
Before attempting carburetor adjustments, makesure
the ignition system, choke, and governor are all
functioning properly. If the carburetor is completely
out of adjustment so the engine will not start, a
reasonably close preliminary setting can be obtained
by turning the adjustment screws in until lightly
seated and then turning them out 1 to 1-1/2 turns (3
turns for gaseous fueled carburetors operating on 800
BTU fuel). Do not force the screws tight against their
seats or damage may occur.
If operating on gas fuel with the gas-gasoline car¬
buretors, be sure to lock the electric choke open
(where used).
12

24 “-25° MARK
ON GEAR COVER
FIGURE 13. VACU-FLO TIMING MARKS
3. Turn in the main fuel adjustment screw (Figure
14) until engine speed drops. Then turn out screw
until engine speed returns to normal.
3. Remove load from the engine.
4. Turn the idle adjustment screw out until engine
speed drops slightly. Then turn the screw in until
speed returns to normal.
Carburetors equipped for gaseous fuel operation only are identical
to the carburetor shown in Figure 14, except the parts not
necessary for gaseous fuel operation (the choke, gasoline adjust¬
ment screws, and the float assembly) have been removed.
Loosen packing nut before turning gasoline
main adjustment and tighten to a snug fit after
adjustment has been made. Hold the adjustment while tightening
packing nut. This procedure will prevent air entry that causes rough
engine operation and fuel leaks. The fuel leaks occur when the
engine is not running and cause difficult starting because the float
level is lowered.
Mixture Screws Adjustment
The same adjustment procedures are used whether
the carburetor is operating on gasoline or gaseous
fuel. Carburetors running on gaseous fuel are factory
set for gas rated at approximately 1000 8TU. Ifthefuel
rating to be used is substantially different, a readjust¬
ment of the fuel mixture is required. To set the
adjustment screws, proceed as follows:
1. Start the engine and allow it to warm up (on
gasoline fueled engines, allow to warm until
choke is fully open).
2. Apply a full load to the engine.
Alternate Method (No Load Adjustment)
1. Start the engine and allow it to warm up.
2. Push in on the governor mechanism to slow the
unit down to about 400 to 500 rpm.
3. Release the governor mechanism to allow the
engine to accelerate. If the engine accelerates
evenly and without a lag, the main adjustment
screw setting is correct. If not, adjust the screw
outward about 1/2 turn and again slow down the
engine and release the mechanism. Continue
until the engine accelerates evenly and without a
time lag after releasing the governor.
4. Push in on the governor mechanism to slow the
unit to 400 to 500 rpm. Set the idle adjustment
screw so the engine is firing on both cylinders and
running smoothly.
FIGURE 14. GAS-FUELED CARBURETOR ADJUSTMENTS
13

Float Level Adjustment
To check float level, remove the entire main fuel
adjustment assembly from the float bowl (unscrew
large nut from float bowl, Figure 14). For correct
carburetor float clearance see Figure 15. Adjustment
is made by bending the tab on the float. The float tab
should just touch fuel inlet valve and not compress
the inlet valve spring.
Do not apply excessive pressure to float valve.
BEND TAB
TO ADJUST
THIS DIMENSION
SHOULD BE 1 / 8 '
(FROM GASKET
TO FLOAT)
BOWL FLANGE
GASKET
A9I3 Rev
TAB CONTACTING
HEAD OF PIN, WITH
FULL WEIGHT OF
FLOAT COMPRESSING
INLET VALVE SPRING.
FIGURE 15. SETTING FLOAT LEVEL
Throttle Stop Screw Adjustment
Set throttle stop screw (located on carburetorthrottle
lever) with no load connected and while running at
rated speed. Turn the screw to give 1/32-inch
(0 79 mm) clearance between the screw and pin
(Figure 17).
OMAN THERMO-MAGNETIC CHOKE
This choke uses a heating element and a heat-
sensitive bi-metal spring to open the choke plate. The
choke solenoid, actuated during engine cranking
only, closes the choke plate according to ambient
temperature.
If the engine has been running, allow it to cool at least
one hour before attempting choke adjustment. Adjust
the choke as follows;
1. Remove the flame arrester and adapter (Figure
14) to expose the carburetor throat.
2. Loosen the screw that secures the choke body
(Figure 16).
3. Rotate the choke body until the proper setting is
achieved. Refer to Figure 16 for correct choke
settings at various ambient temperatures. Use
drill rod or the shank of a drill bit to measure the
choke opening.
GOVERNOR
The governor and vacuum booster control engine
speed. Rated speed and voltage appear on the
nameplate (see Specifications). On a 2 pole
generator, engine speed equals frequency multiplied
by 60 thus 3,600 rpm gives 60-cycle frequency.
Preferred speed does not vary more than 3 cycles
from no-load to full-load operation. Be sure throttle,
linkage, and governor mechanism operate smoothly.
Refer to Figure 17 and make adjustments as follows:
Linkage: 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 that with the engine stopped and
with tension on the governor spring, the stop screw
on the carburetorthrottle lever is 1/32-inch (0.79 mm)
from the stop pin. This setting allows immediate
control by the governor after starting, and syn¬
chronizes travel of the governor arm and the throttle
shaft.
Afubient Temperature (°F)
60
65
70
75
80
85
90
0 ^
15 64
Choke Opening (Inches)
1/8
9/64
5/32
11/64
3/16
13/64
7/32
Ambient Temperature (C°)
16
18
21
24
27
29
32
__35
Choke Opening (mm)
3.2
3.6
4.0
4.4
4.8
5.2
5.6
6.0
LOOSEN THIS
SCREW AND
ROTATE THE
ENTIRE COVER
ASSEMBLY
FIGURE 16 . THERMO-MAGNETIC CHOKE ADJUSTMENTS
14

THROTTLE
STOP SCREW
FUEL IDLE
adjustment
■ T HIS DISTANCE
1/32 INCH (0,79 mm)
AT NO LOAD
CARBURETOR
INTERNAL SPRING
BRACKET
VACUUM
BOOSTER -
CARBURETOR
THROTTLE ARM-
THIS
DISTANCE
DETERMINES
SENSITIVITY
carburetor
throttle
PLATE-
J
J
u
o
r
QjjJJ
□
EXTERNAL
SPRING
BALL JOINT
GOVERNOR
ARM
GOVERNOR ADJUSTMENT
FIGURE 17. GOVERNOR DETAILS
Speed Adjustment: With the set at operating
temperature and no load, and with the booster
external spring disconnected, adjust the tension of
the governor spring. Turn the speed-adjusting nut to
obtain the correct voltage and speed reading.
Sensitivity Adjustment: Check the voltage and speed,
first with no load connected, and again with a full
load. Adjust the sensitivity to give the closest regula¬
tion (least speed and voltage difference between no
load and full load) without causing a hunting condi¬
tion.
To increase sensitivity (to get closer regulation),
move the governor spring toward the governor shaft.
An adjustment for too much sensitivity will cause
alternate increasing and decreasing of engine speed
(hunting).
To decrease sensitivity, move the governor spring
toward the outer end of the governor arm. Too little
sensitivity will result in too much difference in speed
between no load and full load conditions.
Any change in the sensitivity adjustment usually
requires a compensating speed (spring tension)
adjustment.
Vacuum-Booster Adjustment
1. After sensitivity adjustment, reconnect the
booster external spring to the governor linkage
(Figure 17).
2. With generating set running at no load, move
adjustable slide to point where there is no tension
on spring.
3. Apply full-rated load to generating set.
4. If the speed increases more than at no-load,
lessen the speed booster’s internal spring ten¬
sion. To change tension, pull out the spring
bracket and move the pin to a different hole
(Figure 17). If speed decreases when the load is
applied, increase the booster’s internal spring
tension.
15

SERVICE AND MAINTENANCE
PERIODIC MAINTENANCE SCHEDULE
Regularly scheduled maintenance is the key to lower
operating costs and longer service life for the unit.
The schedules can be used as a guide. However,
actual operating conditions should be the deter¬
mining factor in establishing a maintenance
schedule. When operating in very dusty or dirty
conditions, some of the service periods may have to
be reduced.
Cneck the condition of the crankcase oil, fuel filters,
eic . frequently until the proper service time periods
Ceil) be established.
When any abnormalities occur in operation—unusual noises from
e ? j ne or dccesscries. loss of power, overheating, etc. -contact
yc Onan dealer.
CRANKCASE OIL
Check oil level daily and change oil every 100 hours of
engine operation. If operating In extremely dusty,
dirty or cold conditions, change oil every 50 hours.
When adding oil between changes, use the same
brand and weight as that In the crankcase.
Information on the correct grade and weight of oil Is
given in the OPERATION section of this manual. Oil
capacity is 4 U.S. quarts (3.8 liters). See Figure 18.
WARNING~| Never check oil level while engine Is runnif>g.
Hot oil discharged from the engine could
cause personal injury.
SERVICE THESE ITEMS
AFTI
ER EACH CYCLE OF OPERATIONAL HOURS
8 50
100
200
500
1000
Inspect Engine Generally
Xl
Check Fuel Supply
X
Check Oil Level
X
Clean Governor Linkage
X
Service Air Cleaner
X
Change Crankcase Oil
X
Check Battery Electrolyte Level
X
Clean Fuel Filter
X
Change Spark Plugs
X
Check Brushes
X
Clean Crankcase Breather
X
Inspect Breaker Points
X
Clean Commutator Collector Rings
x2
Check Valve Clearance
x2
Remove Carbon and Lead Deposits
1
x2
Clean Carburetor
x2
Inspect Valves, Grind if Necessary
x2
Clean Generator
X
Remove and Clean Oil Base
x2
xl - With set running, visually and audibly check exhaust system and fuel system
for leaks, etc.
x2 - Contact your authorized Onan service center.
16

CAP AND OIL
LEVEL INDICATOR
KEEP OIL
AT THIS LEVEL
NEVER OPERATE
ENGINE WITH OIL
BELOW THIS LEVEL .
-full
-LOW
ALWAYS REPLACE
CAP TIGHTLY, OR
OIL leakage may
OCCUR.
FIGURE 20. VACUUM SPEED BOOSTER
A*74
FIGURE 18. OIL LEVEL INDICATOR
CRANKCASE BREATHER
Clean the crankcase breather cap and valve
assembly, and the breather tube baffle in a solvent
every 200 operational hours. To remove breather cap
and valve assembly, remove breather hose clamp and
breather tube clamp. Soe Figure 19,
SPEED BOOSTER
Use a fine wire to clean the small hole in the short
vacuum tube which fits into the hole in the top of the
engine intake manifold. Do not enlarge this hole. If
there is tension on the external spring when the unit is
operating at no load or light load, it may be due to
improper adjustment, restricted hole in the small
vacuum tube, or a leak in the booster diaphragm or
gasket. See Figure 2u.
FUEL FILTER (Where Applicable)
Every 100 hours, remove the fuel sediment bowl,
empty, clean and dry (Figure 21). Remove the screen
and clean any particles trapped. When replacing the
sediment bowl, be sure the screen and gaskets are in
place.
{^JWARNIN^^
hazard.
Use extreme care when cleaning with a
petroleum base cleanser due to potential fire
FIGURE 21. FUEL FILTER ASSEMBLY
GENERATOR MAINTENANCE
The generator normally needs little care other than a
periodic check of the brushes, commutator and
collector rings. If a major repair job on the generator
should become necessary, have the equipment
checked by a competent electrician who is thorough¬
ly familiar with the operation of electric generating
equipment.
17

SPARK PLUGS
Each time the spark plugs are removed, inspect, clean
and regap (Figure 22). If the plug looks discolored or
has fouled, replace it.
PJGURE 22. CHECKING SPARK PLUG GAP
GOVERNOR LINKAGE
The linkage must be able to move freely through its
entire travel. Every 50 hours of operation, clean the
joints. Lubricate metal ball joints as shown in Figure
23 Do not lubricate plastic ball joints. Also inspect the
linkage for binding, excessive slack and wear.
JOINT APART. CLEAN LINKAGE LUBRICATED
AND LUBRICATE
894
AIR CLEANER
Proper maintenance of the air cleaner is extremely
important. Negligence of regular routine
maintenance will result in reduced engine life.
Allowing the element to become plugged with
^ ' ■ estric* ‘he intake of air into the
engine.
Inspect the element for tears which would permit
particles of dust or dirt to enter the engine. Clean the
element in a suitable solvent, dry and oil as shown in
Figure 24.
Never run the engine with the air cleaner
removed. Dirt will enter the engine and score
the cylinders.
FIGURE 23. GOVERNOR LINKAGE
FIGURE 24. AIR CLEANER ELEMENT