Onan CCK User manual

Orton
Operators
Manual
case
GenSet
4 kW and 5 kW
Mobile Models
927-0120
(SPEC U)
(Reprinted 5-82)
Printed in U.S.A.

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 tne equipment.
A DANGER This symbol warns of Immediate haz¬
ards which will result in severe personal injury or
death .
lAWARNiNGl This symbol refers to a hazard or unsafe
practice which can result in severe personal injury
or death .
1A caution] 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 while engine is running. Fuel contact
with hot engine or exhaust is a potential fire hazard.
• DO NOT SMOKE OR USE AN OPEN FLAME near the gen¬
erator set or fuel tank.
• Fuel lines must be adequately secured and free of leaks.
Fuel connection at the engine should be made with an ap¬
proved flexible, non-conductive line. Do not use copper pip¬
ing on flexible lines as copper will work harden and Become
brittle.
• Be sure all fuel supplies have a positive shutoff valve.
GASOLINE AND LPG FUEL MAY BE ACCIDENTALLY IG¬
NITED BY ELECTRICAL SPARKS, presenting the hazard of
fire or explosion, which can result in severe personal in¬
jury or death. When installing the generator set:
• Do not tie electrical wiring to fuel lines.
• Do not run electrical lines and fuel lines through the same
compartment openings.
• Keep electrical and fuel lines as far apart as possible.
• Place a physical barrier between fuel lines and electrical
lines wherever possible.
• If electrical and fuel lines must pass through the same com¬
partment opening, make certain that they are physically
separated by running them through individual channels, or
by passing each line through a separate piece of tubing.
• 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
♦ Never sleep in the vehicle with the generator set running un¬
less vehicle is equipped with an operating carbon monoxide
detector.
♦ Provide an adequate exhaust system to properly expel dis¬
charged gases. Inspect exhaust system daily for leaks per
the maintenance schedule. Ensure that exhaust manifolds
are secure and not warped. Do not use exhaust gases to
heat a compartment.
♦ Be sure the unit is well ventilated.
MOVING PARTS CAN CAUSE SEVERE PERSONAL IN¬
JURY OR DEATH
• Before starting work on the generator set, disconnect batter¬
ies. This will prevent accidental arcing.
• Keep your hands away from moving parts.
• Make sure that fasteners on the generator set are secure.
Tighten supports and clamps, keep guards in position over
fans, drive belts, etc.
• Do not wear loose clothing or jewelry while working on gen¬
erator sets. 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 ex¬
treme caution around hot manifolds, moving parts, etc.
ELECTRICAL SHOCK CAN CAUSE SEVERE PERSONAL
INJURY OR DEATH
• Disconnect starting battery before removing protective
shields or touching electrical equipment. Use rubber insuia-
tive 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 sur¬
faces to be damp when handling electrical equipment.
• Use extreme caution when working on electrical compo¬
nents. High voltages can cause injury or death.
• Follow all state and local electrical codes. Have all electrical
installations performed by a qualified licensed electrician.
Tag open switches to avoid accidental closure.
• DO NOT CONNECT GENERATOR SET DIRECTLY TO
ANY BUILDING ELECTRICAL SYSTEM. Hazardous volt¬
ages can flow from the generator set into the utility line. This
creates a potential for electrocution or property damage.
Connect only through an approved device and after building
main switch is open. Consult an electrician in regard to
emergency power use.
GENERAL SAFETY PRECAUTIONS
• Have a fire extinguisher nearby. Maintain extinguisher prop¬
erly and become familiar with its use. Extinguishers rated
ABC by the NFPA are appropriate for all applications. Con¬
sult the local fire department for the correct type of extin¬
guisher for various applications.
• Hot coolants under pressure can cause severe personal in¬
jury. DO NOT open a radiator pressure cap while the engine
is running. Stop the engine and carefully bleed the system
pressure.
• Benzene and lead, found in some gasoline, have been iden¬
tified 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 con¬
tact gasoline.
• 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.
• Remove all unnecessary grease and oil from the unit. Accu¬
mulated grease and oil can cause overheating and engine
damage, which presents a potential fire hazard.
• DO NOT store anything in the generator compartment such
as oil or gas cans, oily rags, chains, wooden blocks, portable
propane cylinders, etc. A fire could result or the generator
set operation* (cooling, noise and vibration) may be ad¬
versely affected. Keep the compartment 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.
RV-9

TO THE OWNER
Welcome to the growing family of Onan Power users
.. . We are proud to have you as a customer.
Read this manual carefully and observe all safety
rules within. Operating instructions, adjustments and
periodic maintenance procedures are given so that
you . . . the owner, can keep your unit running like
new and expect many years of dependable service
from it. Remember . . . any machine, regardless of
design or type, will perform only in relation to the
services it receives.
If your generator set needs special attention, ask your
Onan dealer for assistance; the Onan Parts and
Service Organization has been factory-trained to
provide up-to-date know-how for keeping your RV
electric generating set “on the road.” A complete
Parts Catalog is available at nominal cost and may be
ordered under #927-0220.
TABLE OF CONTENTS
General Information. 2
Specifications. 3
Installation Checks. 4
Operation.. 6
Engine Troubleshooting Guide. 11
Maintenance. 12
Periodic Maintenance Schedule. 16
Adjustments. 17
Control Troubleshooting. 21
Generator Set Schematic. 22
Remote Accessories. 23
Parts Information. 25
1 warningX
TO PREVENT FIRE OR ACCIDENT HAZARD. . .
THIS UNIT MUST BE INSTALLED ACCORDING
TO THE MANUFACTURERS DETAILED IN¬
STALLATION PROCEDURES OBSERVING ALL
MINIMUM CLEARANCES.
TO AVOID POSSIBLE PERSONAL INJURY OR
EQUIPMENT DAMAGE, ANY INSTALLATION
AND ALL SERVICE MUST BE PERFORMED BY
QUALIFIED PERSONNEL.
1

GENERAL INFORMATION
YOUR MANUAL
This manual contains operation and other informa¬
tion to properly maintain, service, and make ad¬
justments on you r generator set. Study and follow the
instructions carefully. A well-planned service and
maintenance program will result in longerunit life and
better performance. Because the most important part
of repair is diagnosis, a troubleshooting chart is
included.
Throughout the manual, engine end of the generator
set is the front. Left and right sides are determined
when facing the engine (front) end.
When contacting yourOnan dealer, distributor, orthe
factory about the generator set, always supply the
complete model number and serial number as shown
on the nameplate (see Model Designation preceding).
This information is necessary to identify your
generator set among the many types manufactured
by Onan.
FIGURE 1.
TYPICAL. CCK FOR RECREATIONAL VEHICLES
RE AKER POINT
BOX
EXHAUST.
START-STOP
SWITCH
SOLID STATE
CONTROL
UNIT
NAMEPLATE'
GENERATOR
COOLING AIR
■ E L ECTRIC
FUEL PUMP
OIL DRAIN
VIBRATION
ISOLATOR
2

SPECIFICATIONS
(Dimensions in parenthesis are metric values)
ENGINE DETAILS
Manufacturer.
Number of Cylinders.
Displacement (in )...
Cylinder Bore.
Piston Stroke.
Compression Ratio ..
Engine Speed.
Engine Design.
Starting Method.
. Onan
. T wo
. 49 8 (816 cm )
. 3.25 inch (82.5 mm)
... 3.00 inch (76.2 mm)
.. 5.5 to 1
... 1800 i pm
Four Cycle, Air Cooled, L-Head, Horizontally Opposed
. Exciter Cranking (Generator)
GENERATOR DETAILS
Manufacturer. Onan
Generator Design. Revolving Armature, Four Pole. 1800 rpm
Rating (Watts)
4.0 CCK. 4000
5.0 CCK. 5000
Voltage (AC). 120/240 Volts
Current Rating (Amperes)
4.0 CCK
120 Volts. 33.3
240 Volts. 16.7
5.0 CCK
120 Volts. 41.6
240 Volts. 20.8
Phase. Single
Output Wires. Four Wire, Reconnectible
Output Rating. Unity Power Factor
Cranking Current.. 75-100 Amperes
Break-away Current. 300-350 Amperes
CAPACITIES AND REQUIREMENTS
Oil Capacity.
Recommended Battery.
Battery Charged Rate Fixed .
Average Fuel Consumption @ Rated Load
4.0 CCK.
5.0 CCK.
Air Inlet Size Required (Minimum)
4.0 CCK.
5.0 CCK.
. 4 Quarts (3.78 Litres)
12 Volt, 74 Amp/hr (266.40 kC)
. 1-1-1/2 amperes
.0.88 gph
.1 05 gph
. 100 in 2 (645 cm 2 )
. 100 in 1 ' (645 cm 2 )
TUNE-UP SPECIFICATIONS
Spark Plug Gap.
Breaker Point Gap.
Ignition Timing.
Valve Tappet Adjustment
Intake.
Exhaust.
.025 inch (0.64 mm)
.020 inch (0.51 mm)
. 19° BTC
.007 inch (0.18 mm)
.016 inch (0.41 mm)
3

INSTALLATION CHECKS
INSTALLATION
Nearly all Onan electric generating sets are installed
by the motor home manufacturer. Although the
manufacturer must follow safety codes when install¬
ing, certain installation problems could arise after the
unit is installed and subjected to vibration. There are a
few areas that you as the operator should be concern¬
ed with. If in doubt about any aspect of your generator
set’s operation or safety, contact your nearest
authorized Onan Service Center. A daily inspection of
your installation should include the following:
EXHAUST
Check for leaks around manifolds, gaskets, and
welds. Make sure exhaust lines are not heating
surrounding areas excessively. If so, have corrected
immediately. Remember EXHAUST GASES CON¬
TAIN DEADLY CARBON MONOXIDE. Be sure all
holes to the inside of RV from set compartment are
sealed to prevent poisonous exhaust gases from
entering vehicles.
WARNING Ail exhaus * shielding supplied with unit
MUST be properly installed to prevent
overheating of compartment walls or the possibility of fire.
FUEL SYSTEM
With set running, check for leaks. Raw fuel will cause
fumes which could EXPLODE. Check around car¬
buretor and fuel pump inlets. Make sure fuel lines are
not rubbing against anything which could cause
breakage.
ELECTRICAL
AC Output: All AC leads (Ml, M2, M3 and M4)
terminate in generator sets junction box. These wires
should be connected to distribution box witi. mul¬
tistrand wire enclosed in a flexible conduit. Check all
wires (to and from the generator set) for fraying and
loose connections. For information on load connec¬
tions refer to operation section following.
Battery Connections: Battery positive (+) connection
connects to start solenoid. Battery negative connects
to location on rear of generator. Check terminals on
set and battery for clean and tight connections.
WARNING I Separate installation area or compartment
from living quarters by a vapor-tight wall to
prevent entrance of noxious fumes to interior.
3 MOUNTING HOLES FOR
4 MOUNTING HOLES FOR
MOUNTING PLATE
EXH MANIFOLD AND EXTENSION
Pf>E OPTIONAL LOCATION
REMOTE TERM BLOCK
iNTROL PANEL
-AIR CLEANER
OUTPUT BOX
a KNOCKOUTS
■ 8ATT POS TERM
-FUEL INLET Vq NPTF
AIR
-BATT NEG TERM
MODEL NO.
MODEL NC.W/PLATE
DIM A DRY WT.
4L0CCK-3CR/I6000S
4.0CCK-3CR/
29.06(738) 290 LBS (131 kg)
5.0CCK-3CR/I6000S
5.0CCK-3CR/
31.44(799)
315 LBS (142 kg)
ARE MILLIMETRES
FIGURE 2. INSTALLATION OUTLINE
4

Do NOT use maintenance free, unvented
batteries with this generator set. Malfunction
of the starting-charging system can produce high charging
currents, causing excessive gassing. An unvented battery can build
up sufficient pressure to explode.
Grounding: Generator must be effectively bonded to
recreational vehicle chassis.
Vehicle chassis (frame) ground and the battery and generator set
ground should all be electrically connected to be at 0 ground
potential. All Onan units are designed for negative ground
application.
Mount the battery in a separate compartment
from the set or any spark-producing device to
prevent fire or explosion.
VENTILATION
The biggest enemy of electric generating sets in¬
stalled in motor homes is excessive heat. Make sure
the set’s air inlet and outlet are not plugged with dust,
dirt, bugs, leaves or anything that could restrict
cooling air.
Don’t use discharged cooling air for compart¬
ment heating since it could contain
poisonous exhaust gases.
Do not terminate exhaust under vehicle, as
carbon monoxide gas is poisonous. Direct
exhaust gases away from window and door openings.
I wad|ji||/; On all listed models with exhaust shielding
supplied with unit, shielding MUST be
property installed to prevent overheating of compartment walls or
the possibility of fire. Refer to appropriate installation guide for
each model for details.
DO NOT DISCONNECT BATTERY CABLES
FROM BATTERY WHILE GENERATOR SET
IS CRANKING OR RUNNING; SPARKS MAY CAUSE AN EXPLO¬
SION.
FIGURE 3. BATTERY AND GROUND CONNECTION
5

OPERATION
[BEFORE STARTING
[Crankcase Oil
Oil capacity of the CCK generator set is 4 U.S. quarts
(3.79 lit). Fill the crankcase until the oil reaches the
“FULL” mark on the oil level indicator (Fiqure 4) DO
NOT OVERFILL.
WARNING | Do NOT check oil whi *e t he generator set is
hhhhmhJ operating. Hot oil could cause bums by
: blowing out of oil fill tube due to crankcase pressure.
CAP AND OIL
LEVEL INDICATOR;
KEEP OIL
AT THIS LEVEL
NEVER OPERATE
ENGINE WITH OIL
BELOW THIS LEVEI_
ALWAYS REPLACE
CAP TIGHTLY, OR
OIL LEAKAGE MAY
OCCUR.
Check oil level daily and change oil every 100 normal
operating hours. See Figure 5 for location of oil drain.
If operating in extremely dustyordirtyconditions, the
oil might have to be changed sooner. When adding oil
between changes, use the same brand as in the
crankcase. Various brands of oil might not be com¬
patible when mixed.
TEMPERATURE fiBinc
Below 0°F (-18° C) .5W or 5W-30
0° to 32° F (-18° C to 0°C) .lOW or 10W-40
Above 32° F (0°C) . 30
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.
Use of the same grade and quality oil as that used in
your recreational vehicle engine is acceptable as long
as unit is serviced regularly and oil meets API
designation SE or SE/CC. Other factors (primarily
temperature) should also be considered when selec¬
ting appropriate engine oil.
FIGURE 4. CHECKING OIL LEVEL
Use a heavy duty oil with the API (American
Petroleum Institute) designation SE or SE/CC
(gasoline operation only). If this oil is not available,
SD or SD/CC designated oil can be used.
FIGURE 5. OIL DRAIN AND FILL
Recommended Fuel
All Onan AC electric generating sets for recreational
vehicles use gasoline fuel. Because any AC electric
generating set runs at a constant speed, lead deposits
tend to build up in the combustion chambers. Forthis
reason, use clean, fresh, lead free or low-lead gas¬
oline. Regular grade gasoline may also be used, but
DO NOT use highly leaded premium types of fuel.
For new engines, the most satisfactory results are
obtained by using nonleaded gasoline. For older
engines that have previously used leaded gasoline,
the cylinder heads must be taken off and all lead
deposits removed from engine before switching to
nonleaded gasoline.
leaded gasoline, if
damage.
Lead deposits must be removed from an
engine before switching from leaded to non-
not, preignition can occur causing engine
| WARNING \ ^ a so * s n e leakage to or around the compart-
ment is a definite hazard. The ventilation
system should provide a constant flow of air to expei any
accumulation of fuel vapor while the vehicle is in transit. Com¬
partments must be vapor tight to the interior to keep fumes from
within the vehicle.
8

starting
Push the start-stop switch to the start position.
Release the switch when engine starts. If engine fails
to start, inhibitor oil used at the factory may have
fouled the spark plugs. Remove the plugs, clean in a
suitable solvent, dry thoroughly and re-install. Heavy
exhaust smoke when the engine is first started is
normal and caused by the inhibitor oil.
CONTROL FUSES
A 5 amp. 32 volt fuse (F2) is connected in the ignition circuit of the
control. If unit cranks but fails to start when switch SI is pushed,
ch»*ck fuse F2. It remote battery condition meter does not operate.
< h« c k fuse FI.
STOPPING
Push the start-stop switch to the stop position and
hold until unit stops completely.
BREAK-IN PROCEDURE
Controlled break-in with the proper oil and a con¬
scientiously applied maintenance program will help
to assure satisfactory service from yourOnan electric
generating set. Break-in as follows:
1. O n e half hour at 1/2 load (with one air conditioner
only).
2 One half hour ai3/4 load (with one air conditioner
and approximately 1000 watts additional load).
3. Change crankcase oil after the first 50 hours of
operation.
APPLYING LOAD
If practical, allow set to warm up before connecting a
heavy load. Continuous generator overloading may
cause high operating temperatures that can damage
the windings. Keep the load within nameplate rating.
VOLTAGE SELECTION
Voltage selection on reconnectible single-phase
generators is for use as 120/240 volts, 3 wire; or 120
volts, 2 wire. 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. When two or more single¬
phase circuits are available, divide the load equally
between them. See Figure 6.
LOAD CONNECTIONS
1. Generator set load wires Ml, M2, M3 and M4
terminate within the junction box. Connect and
join wires within junction box in an approved
manner for desired voltage code. See Figure 6.
2. Wires must be adequate size, properly insulated'
and supported.
3. Mount switches and controls securely to prevent
damage from vibration and road shocks. All
switches must be vibration proof to prevent
accidental opening or closing while the vehic e is
in motion.
4. A ll wiring must meet applicable local electrical
codes. Have a qualified electrician install ano
inspect the wiring.
EXERCISE
Infrequent use results in hard starting. Operate the
generator set one 30-minute period each week. Run
longer if battery needs charging. Exercising for one
long period each week is better than several short
periods.
BATTERY CHARGING
The battery charge rate is automatically controlled by
a solid-state voltage regulator. The high charge rate
was set at the factory for average operating con¬
ditions.
HIGH OPERATING TEMPERATURES
1. See that nothing obstructs air flow to and from the
set.
2. Keep cooling fins clean. Air housing should be
properly installed and undamaged.
3. Keep ignition timing properly adjusted.
LOW OPERATING TEMPERA’’ URES
1. Use correct SAE oil for tempera e conditions.
Change oil only when engine is warm. If an
unexpected temperature drop causes an
emergency, move vehicle to a warm location.
2. Use fresh gasoline. Protect against moisture
condensation. Below 0°F (-18°C), adjust car¬
buretor main jet for a 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.
OPERATION IN DUST AND DIRT
1. Keep unit clean. Keep cooling surfaces clean.
2. Service air cleaner as frequently as necessary.
3. Change crankcase oil every 50 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.
HIGH ALTITUDES
For operation at altitudes of 2500 feet (775 m) above
sea level, close carburetor main jet adjustment slight¬
ly to maintain proper air-to-fue! ratio (refer to the
ADJUSTMENTS section). Maximum power will be
reduced approximately four percent for each 1000
feet (310 m) above sea level after the first 1000 feet.

POWER REQUIREMENTS FOR APPLIANCES
Appliance or Approximate
Tool Running Wattage
Refrigerator.. 600-1000
Electric broom . 200-500
Coffee percolator. 550-700
Electric frying pan. 1000-1350
Hairdryer. 350-500
Electric stove (per element). 350-1000
Electric iron. 500-1200
Radio. 50-200
Electric water heater. 1 0 0 0-1500
Space heater. 1000-1500
Electric blanket. 50-200
Television. 200-600
Electric drill. 250-750
Battery charger. Up to 800
Electric water pump. 500-600
Air Conditioner.1400-2200
Converter. 300-350
FIGURE 6. SINGLE-PHASE, “-3C” VOLTAGE CODE GENERATOR CONNECTIONS

FIGURE 7. SEQUENCE OF OPERATION
OUT-OF-SERVICE PROTECTION
Protect a generator set that will be out of service for
more than 30 days from damage caused by rust or
corrosion. Use the following procedure to properly
protect the set.
1. Run the generator set with at least a 50 percent
load until thoroughly warm (usually about 1
hour).
2. Turn off fuel supply and allow the engine to run
out of fuel. Also operate the choke manually as
the engine stops to help drain the carburetor
completely.
3. Drain the oil from oil base while engine is still
warm. Replace the oil filter if so equipped.
Replace drain plug and refill. Attach a warning tag
stating type and viscosity of oil used.
4. Remove spark plugs. Pour 1 ounce of rust in¬
hibitor oil (orSAE#10) into each cylinder. (Spray
cans work well for this application.) Turn engine
over by hand at least 2 complete revolutions.
Replace the spark plugs.
5. Replace the air cleaner at least on an annual
basis.
6. Plug the exhaust outlet to prevent entrance of
moisture, dirt, bugs, etc.
7. Clean and oil all exposed engine parts including
carburetor and governor linkage.
8. Wipe generator brushes, slip rings, housing, etc.
Do not apply any lubricant or preservative.
9. Remove the battery and store in a cool dry place.
Coat the battery terminals and cable connections
with vasoline or grease to prevent any corrosion.
Recharge the battery at least monthly or maintain
with a trickle type battery charger.
10. P r ovide a suitable cover if the unit is exposed to
the elements.
RETURNING THE UNIT TO SERVICE
1. Remove the cover and all protective wrapping.
Wipe the oil film off all exposed engine parts.
Remove the plug from the exhaust outlet.
2. Visually inspect the unit for any damage. Checkto
be sure the carburetor and governor linkage are
free. Remove the generator end bell band and
check to be sure the brushes work freely in their
holders.
3. Check the tag to ensure oil of the proper brand
and grade has been installed. Check the oil level.
4. Install the battery (be sure battery is fully charg¬
ed), observing proper polarity. Ground is
negative.
5. Remove spark plugs, clean and gap. Turn the
engine over by hand several times. Reinstall spark
plugs.
9

6. Turn on fuel, disconnect electric fuel pump lead
and electric fuel solenoid shut-off lead if unit is so
equipped. Jumper the fuel pump and electric fuel
solenoid shut-off leads to the battery to prime the
unit. Reconnect the leads.
7. Remove all load and start the generator set at the
unit. Initial start may be slow due to oil or rust
inhibitor in the cylinders. Excessive smoke and
rough operation will occur until the oil or rust
inhibitor is burned off.
8. Apply a 50 percent load after the set runs smooth.
Allow the generator set to warm up (1 hour) with
the load connected. Check speed and voltage.
9. Unit is now ready for service.

ENGINE TROUBLESHOOTING GUIDE
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GASOLINE ENGINE
TROUBLESHOOTING
GUIDE
STARTING SYSTEM
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■ HI ■■□ ■ ■ □ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ I
■ a n ■■□ ■ ■□■■ ■ ■ ■ ■ ■ ■ ■ ■ um
Loose or Corroded Battery Connection
Low or Discharged Battery
Faulty Starter
Faulty Start Solenoid
' ■■ . f;^ : ; '_IGNiTiON SYSTEM
Ignition Timing Wrong
Wrong Spark Plug Gap
Worn Points or Improper Gap Settin
■ ■ ■ ■
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FUEL SYSTEM 1
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Rich Fuel Mixture or Choke Stuck
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Dirty Carburetor
Dirty Air Cleaner_
Dirty Fuel Filter
Defective Fuel Pump
INTERNAL ENGINE
Wrong Valve Clearance
Broken Valve Sprin
Valve or Valve Seal Leaking
Wrong Bearing Clearance
COOLING SYSTEM (AIR COOLED )
Poor Air Circulation
Dirty or Oi
Blown Head
i?COOLING SYSTEM (WATER COOLED )
Faulty Thermostat
Worn Water Pump or Pump Seal_
Water Passages Restricted
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B ^m i
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Relief Valve Stuck
Faulty Oil Pump
Dirty Oil or Fi Iter
Oil Too Heav
Dirty Crankcase Breather Valve
Z^f ::THR6TTLE AND GOVERNOR
Linkage Out of Adjustment
Linkage Worn or Disconnected
Linkage Binding

BATTERY CARE
To increase battery life, the operator can perform a
number of routine checks and some preventive
maintenance.
1. Keep the battery case clean and dry.
2. Make sure the battery cable connections are
clean and tight. Use a terminal puller when
removing cables for any reason.
3. Coat the battery terminals with a mineral grease
or petroleum jelly to reduce corrosion and oxida¬
tion.
4. Identify each battery cable to be positive or
negative before making any connection. Always
connect the ground (negative) cable last.
5. Maintain the electrolyte level by adding water
(drinking quality or better) as needed for filling to
split level marker. The water ingredient of the
electrolyte evaporates, but the sulphuric acid
ingredient remains. Therefore, add water, not
electrolyte.
6. Avoid overcharging when recharging. Stop the
boost charge when the specific gravity is 1.260
and the electrolyte is 80° F (26.7° C).
FUEL SOLENOID
The positivefuel shutoff valveprevents flooding of the
generator set, when not in use, should the vehicle fuel
tank become pressurized.
ONAN ELECTRIC FUEL PUMP
Every 100 operating hours or sooner, clean the filters.
To gain access to the filters in the Onan fuel pump
(Figure 8), remove the four top Phillips head screws
and lift off the top filter assembly. Clean the two
screen filters, reinstall and remount the top filter
assembly. Be sure the gasket is in place.
COOLING SYSTEM
The generator set is cooled by a flywheel blower fan
which pulls air over the cylinders and cooling fins.
The air path is directed by sheet metal shrouds and
plates. These shrouds and plates must always be
installed properly so unit does not overheat.
Check and ciean (if necessary) the cooling fins at
least every 100 hours of operation. Remove any dust,
dirt or oil which may have accumulated. Check
compartment air inlet and power plant air outlet for
buildup of dirt, chaff, etc.
AIR CLEANER
Under normal operating conditions clean the airfilter
every 50 hours. To clean, remove foam strip and
element and tap element on a clean flat surface to
dislodge the dirt particles. Do not use high pressure
compressed air as damage may occurto paperpleats.
Replace element every 200 hours. Replace more often
in dusty conditions.
WARNING \ Re P lace with Onan fuel pump only (as listed
in PARTS INFORMATION section). Standard
automotive pumps are high pressure type which may force
excessive gasoline into engine causing a fire or explosion.
Replace with “UL Tested” Onan air filter only.
Improper filter may bum due to backfire.
AIR CLEANER AIR CLEANER
FiGURE 9. AIR CLEANER ELEMENT

SPARK PLUGS
Replace spark plugs every 100 hours or at least once a
year. A badly leaded plug will cause misfiring, poor
operation or stopping when a load is applied.
• Black deposits indicate a rich mixture.
• Wet plug indicates misfiring.
• Badly or frequently fouled plug indicates the need
for a major tune-up.
Each time the spark plugs are removed, inspect, clean
and regap (Figure 10). If the plug looks discolored or
has fouled, replace it.
GOVERNOR LINKAGE
The linkage must be able to move freely through its
entire travel. Every 50 hours of operation, clean the
joints and lubricate as shown in Figure 11. Also
inspect the linkage for binding, excessive slack and
wear.
CRANKCASE BREATHER
Lift off the rubber breather cap and carefully pry valve
from cap (Figure 12). Wash and rinse the whole valve
in a suitable solvent. Dry the valve and re-insert. Be
sure the valve flapper is toward the engine.
FIGURE 12. CRANKCASE BREATHER
SPEED BOOSTER (5.0 CCK Only)
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.
CLEAN
FIGURE 11. GOVERNOR LINKAGE
FIGURE 13. VACUUM SPEED BOOSTER

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 generator
equipment.
Brush Replacement
Install new brushes when the old ones are worn to the
dimensions shown in Figure 14. Remove the end bell
band to expose the brush holders. Remove the three
screws holding each brush holder in place (Figure
14). Remove the old brushes and clean the holders so
the new brushes can move easily in their holders.
Install the new brushes in the same manner as the old
ones. Always use the correct brush as listed in the
PARTS INFORMATION section. Never substitute a
brush which may appear to be the same for it may
have different characteristics. New brushes are
shaped to fit and seldom need sanding to seat
properly. If some brush sparking occurs after replac¬
ing brushes, run the set under a light load until the
brushes wear to a good seat.
Collector rings acquire a glossy brown finish in
normal operation. Do not attempt to maintain a bright
newly machined appearing surface. Ordinary clean¬
ing with a dry, lint free cloth is usually sufficient. Very
fine sandpaper (#00) may be used to remove slight
roughness.
MEASURE FROM TOP FACE OF
BRUSH BLOCK TO TOP OF BRUSH
DC
AC
NEW 5/8”
11/16”
y 2 WEAR
13/16”
! 7/8”
i
REPLACE
1 ”
i
j 1 1/16”
•
FIGURE 14. BRUSH LENGTH
14

EXHAUST SPARK ARRESTERS
Exhaust spark arresters are necessary when
operating in some parks and camps. Two basic types
are used in the recreation vehicle industry. One is a
spin-out type spark arrester, the other is a screen type
spark arrester. All require periodic clean-out (every
50 to 100 operating hours) to maintain maximum
efficiency.
Spin-Out Type Spark Arrester
This type removes carbon particles by centrifugal
force, catching the particles in a holding chamber.
Removing a pipe plug from the arrester and operating
the electric set (at a convenient time and place) cleans
out the deposits. It is important to note this arrester
does not plug up when the holding chamber is full and
does not cause harmful, high exhaust back pressure.
When full, particles pass through the arrester.
Screen Type Spark Arrester
This arrester has a screen which traps carbon par¬
ticles as they pass through. The screen is removed,
cleaned or replaced after it has filled. A disadvantage
of this type is the screen plugs as it collects the
particles and gradually increases exhaust back
pressure. Back pressure causes a loss of engine
power and can cause burned or damaged valves if
pressure is high enough. It is very important this type
be cleaned as recommended.
IMPORTANT: Certain states (particularly California) have state
ordinances pertaining to the type and usage of exhaust
muftler/spark arresters on internal combustion engines or engine
driven equipment when used in a recreational vehicle such as
electric generating sets. Be sure your installation meets all Federal,
State and local codes pertaining to your unit. Failure to provide and
maintain a spark arrester may be in violation of the law.
warning!
EXHAUST GAS IS DEADLY!
Exhaust gases contain carbon monoxide, an odorless and colorless gas. Carbon
monoxide is poisonous and can cause unconsciousness and death. Symptoms of
carbon monoxide poisoning can include:
• Dizziness • Throbbing in Temples
• Nausea • Muscular Twitching
• Headache • Vomiting
• Weakness and Sleepiness • inability to Think Coherently
IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT
INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical atten¬
tion. Shut down the unit and do not operate until it has been inspected and
repaired.
Never sleep in vehicle with the generator set running unless the vehicle interior is
equipped with an operating carbon monoxide detector. Protection against carbon
monoxide inhalation also includes proper exhaust system installation and visual
and audible inspection of the complete exhaust system at the start of each
generator set operation.
1-RV
15

Regularly scheduled maintenance is the key to lower
operating costs and longer service life for the unit.
The following schedule can be used as a guide.
However, actual operating conditions under which a
unit is run should be the determining factor in
establishing a maintenance schedule. When
operating in very dusty or dirty conditions, some of
the service periods may have to be reduced. Check
the condition of the crankcase oil, the filters, etc.
frequently until the proper service time periods can be
established.
For any abnormalities in operation, unusual noises
from engine or accessories, loss of power,
overheating, etc., contact your nearest authorized
Onan Service Center.
SERVICE THESE ITEMS
AFTER EACH CYCLE OF INDICATED HOURS
8 50
100 200 400
General Inspection
Xl
Check Oil Level
X
Check Battery Electrolyte Level
X
Change Crankcase Oil
x2
Check Spark Plugs
x4
Check Breaker Points
x3
Clean Breather Valve
X
Clean Governor Linkage
X
Service Air Cleaner (Oil Bath)
x2
Replace Air Cleaner Element (Dry)
x2
Clean Cooling Fins
x2
Change Oil Filter (If Used)
x2
Replace Breaker Points
x4
Clean Crankcase Breather
X
Remove Carbon Deposits From Heads
X
Adjust Tappets
X
Replace Fuel Filter (If Used)
x4
Clean Carburetor
X
Check Generator Brushes (Replace if Necessary)
As Required
xl - With set running, visually and audibly check exhaust system for leaks.
x2 - Perform more often in extremely dusty conditions.
x3 - Replace if necessary.
x4 - Replace annually or prior to storage.
| WARNING I 4** ©xhaust system connections MUST be checked regularly for any leaks and
Wthb — m - m i l l I tightened as necessary. Do NOT terminate exhaust pipe under vehicle or near any
window or door openings, inspect the vapor fight seals around all openings made in the set's
compartment for wiring, conduit, etc., to prevent entrance of any noxious fumes to motor home
inferior.
16

ADJUSTMENTS
f
BREAKER POINTS
1. Remove the two screws and the cover on the
breaker box.
2. Remove the two spark plugs so engine can be
easily rotated by hand.
3. Turn flywheel in a clockwise direction ap¬
proximately 1/4 turn after top center (TC).
4. To adjust gap refer to Figure 15. Loosen screws
(A) and turn cam (B) until point gap measures
.020-inch with a flat thickness gauge. Retighten
screws (A) and recheck gap.
5. If points appear to be burned and pitted, replace
them with a new set.
6. Replace spark plugs and breaker box cover.
IGNITION TIMING
Both spark plugs on the CCK fire simultaneously,
thus the need for a distributor is eliminated. Spark
advance is set at 19° BTC (before top center) and
should be maintained for best engine performance.
Always check timing after replacing ignition points or
if noticing poor engine performance. Proceed as
follows:
Timing Procedure—Engine Running
1. To accurately check the ignition timing, use a
timing light when the engine is running . Connect
the timing light according to its manufacturer’s
instructions. Either spark plug can be used as
they fire simultaneously.
2. Remove the plug from the timing hole (Figure 16).
3. Start the engine and check the timing. The mark
on the flywheel should line up with the 19° BTC
mark on the cover.
4. If timing needs adjustment, loosen the mounting
screws on breaker box and move left to advance
or right to retard the timing.
5. Start engine to be sure mark on flywheel lines up
with 19° mark on cover.
6. Tighten all screws; replace timing plug.
Timing Procedure—Engine Not Running
1. Connect a continuity test lamp set across the
ignition breaker points. Touch one test prod to
the breaker box terminal to which the coil lead is
connected and touch the other test prod to a good
ground on the engine.
2. Turn crankshaft against rotation (coun¬
terclockwise) until the points close. Then slowly
turn the crankshaft with rotation (clockwise).
3. The lamp should go out just as the points break
which is the time at which ignition occurs
(19° BTC).
PLACE A DROP OF
LIGHT OILON
BREAKER ARM PIVOT
SHAFT EVERY 200
OPERATING HOURS
TO ADJUST GAP
LOOSEN SCREWS ®
TURN CAM (§)
RETARD SPARK —
— ADVANCE SPARK
SET BREAKER POINT
GAP WIDTH AT 0.020’
LOOSEN THESE-
SCREWS TO ADJUST
POSITION OF
BREAKER BOX f
REFERENCE MARK
FIGURE 15. BREAKER BOX AND TIMING MARK
FIGURE 16. TIMING ACCESS HOLE
17

CARBURETOR
The carburetor has an adjustable idle and main jet. If
the engine runs unevenly at half or full load due to
faulty carburetion, the main adjusting screw requires
adjustment. The idle adjustment screw, normally
requires little attention otherthan a periodic cleaning.
A hunting condition (alternate increase and decrease
in engine speed) at no load can sometimes be
corrected by an idle adjustment. Make all adjustments
with the engine at normal operating temperature.
To adjust the main screw, connect a full or nearly full
load to the engine. Turn the main adjusting screw out
about two full turns. Then turn it in slowly until the
engine begins to lose power and speed. Then turn it
out slowly until theengine runs smoothly at full power
and speed. If the engine develops a hunting condition
try correcting by opening the main adjusting screw a
little more. Do not open more than 1/2 turn beyond
the maximum power point. If this does not correct the
condition, adjust the governor sensitivity.
Adjust the idle screw with no load connected to the
engine. Turn the screw in until the engine loses
considerable speed. Then turn it out until the engine
runs smoothly.
DIMENSION IS 5/16”
(METAL FLOATS
OR 1/4” (STYRAFOAM
PLASTIC FLOAT)
I CAUTION T Loosen
packing nut
before turning main fuel adjust¬
ment and tighten to a snug fit after
adjustment has been made. Hold
[ • :
11
| the adjustment while tightening
J
©
yv pacKing nui.
1-
1
J ^GASOLINE IDLE
ADJUSTMENT
-GASOLINE MAIN
ADJ USTMENT
STARTING POSITION
THROTTLE
STOP SCREW .
IDLING POSITION
THROTTLE
PLATE
A775 -1
THROTTLE
STOP BOSS _ J
MANIFOLD ^1-
_ U _
SET THIS DISTANCE
AT 1/32” WHEN PLANT IS
RUNNING AT NO LOAD
FIGURE 17. CARBURETOR ADJUSTMENTS
ELECTRIC CHOKE
If extremes in starting temperatures require a read¬
justment of the choke, slightly loosen the two cover
retaining screws. For less choking action, turn the
cover assembly a few degrees in a clockwise direc¬
tion. For more choking action, turn counterclockwise.
Retighten the cover screws.
Loosen these
screws and
rotate the
entire cover
assembly
FIGURE 18. ELECTRIC CHOKE
If the engine starts and runs roughly after a minute or two of
operation, the choke is set too rich. If the engine starts, and
assuming that fuel, ignition and compression are adequate, but the
engine sputters or stops before it warms up, the choke is set too
lean.
GOVERNOR AND BOOSTER
The governor and booster control the speed of the
engine. A speed adjustment includes adjusting both
devices (Figure 19).
Governor Adjustment
Before making adjustments, run the set about 15
minutes with a light load connected to reach normal
operating temperature. (If governor is completely out
of adjustment, make a preliminary adjustment at no
load to first attain a safe voltage operating range.)
Engine speed determines the output voltage and
current frequency of the generator. By increasing the
engine speed, generator voltage and frequency are
increased, and by decreasing the engine speed,
generator voltage and frequency are decreased'
Connect an accurate voltmeter or frequency meter
(preferably both) to the generator output in order to
correctly adjust the governor. A small speed drop not
noticeable without instruments will result in an objec¬
tionable voltage drop. Use a tachometer to check
engine speed.
A binding in the bearings of the governor shaft, in the
ball joint, or in the carburetor throttle assembly
causes erratic governor action or alternate increase
and decrease in speed (hunting). A lean carburetor
adjustment may also cause hunting. Springs of all
kinds have a tendency to lose their calibrated tension
through fatigue after long usage. If all governor and
carburetor adjustments are properly made, and the
governor action is still erratic, replacing the spring
with a new one and resetting the adjustments will
usually correct the trouble.
1. Adjust the carburetor main jet for the best fuel
mixture while operating the set with a full rated
load connected.
2. Adjust the carburetor idle needle with no load
connected.