Onan 3.0 AJ User manual

SAFETY PRECAUTIONS
The following symbols in this manual signal poten¬
tially dangerous conditions to the operator or equip¬
ment. Read this manual carefully. Know when these
conditions can exist. Then, take necessary steps to
protect personnel as well as equipment.
WARNING I Onan uses this symbol
throughout this manual to
warn of possible serious personal injury.
This symbol refers to possible
equipment damage.
Fuels, electrical equipment, batteries, exhaust gases
and moving parts present potential hazards that could
result in serious, personal injury Take care in follow¬
ing these recommended procedures.
• Use Extreme Caution Near Gasoline. A constant
potential explosive or fire hazard exists.
Do not fill fuel tank near unit with engine running.
Do not smoke or use open flame near the unit or
the fuel tank.
Be sure all fuel supplies have a positive shutoff
valve.
Fuel lines must be of steel piping, adequately
secured and free of leaks. Use a flexible section of
fuel line between generator set and stationary fuel
line in the vehicle. This flexible section must be
100% NON-METALLIC to prevent electrical
currents from using it as a conductor.
Have a fire extinguisher nearby. Be sure ex¬
tinguisher is properly maintained and be familiar
with its proper use. Extinguishers rated ABC by
the NFPA are appropriate for all applications.
Consult the local fire department for the correct
type of extinguisher for various applications.
• Guard Against Electric Shock
Remove electric power before removing protec¬
tive shields or touching electrical equipment. Use
rubber insulative mats placed on dry wood plat¬
forms 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 damp when handling electrical
equipment.
Jewelry is a good conductor of electricity and
should be removed when working on electrical
equipment.
Always use an appropriately sized, approved
double-throw transfer switch with any standby
generator set. DO NOT PLUG PORTABLE OR
STANDBY SETS DIRECTLY INTO A HOUSE
RECEPTACLE TO PROVIDE EMERGENCY
POWER. It is possible for current to flow from
generator into the utility line. This creates ex¬
treme hazards to anyone working on lines to
restore power.
Use extreme caution when working on electrical
components. High voltages cause injury or death.
Follow all state and local electrical codes. Have all
electrical installations performed by a qualified
licensed electrician.
• Do Not Smoke While Servicing Batteries
Lead acid batteries emit a highly explosive
hydrogen gas that can be ignited by electrical
arcing or by smoking.
• Exhaust Gases Are Toxic
Provide an adequate exhaust system to properly
expel discharged gases. Check exhaust system
regularly for leaks. Ensure that exhaust manifolds
are secure and not warped.
Be sure the unit is well ventilated.
• Keep The Unit And Surrounding Area Clean
Remove all oil deposits. Remove all unnecessary
grease and oil from the unit. Accumulated grease
and oil can cause overheating and subsequent
engine damage and may present a potential fire
hazard.
Do NOT store anything in the generator com¬
partment such as oil or gas cans, oily rags,
chains, wooden blocks, propane tanks, etc. A
fire could result or the generator set operation
(cooling, noise and vibration) may be adversely
affected. Keep the compartment floor clean and
dry.
• Protect Against Moving Parts
Avoid moving parts of the unit. Loose jackets,
shirts or sleeves should not be permitted because
of the danger of becoming caught in moving
parts.
Make sure all nuts and bolts are secure. Keep
power shields and guards in position.
If adjustments must be made while the unit is
running, use extreme caution around hot
manifolds, moving parts, etc.
Do not work on this equipment when mentally or
physically fatigued.

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 924-0222.
TABLE OF CONTENTS
General Information. 2
Specifications. 3
Installation Checks. 4
Operation. 6
Adjustments. 9
Engine Troubleshooting Guide. 12
Maintenance. 13
Control Troubleshooting. 17
Remote Accessories. 19
Parts Information. 21
EARNING
TO PREVENT FIRE OR ACCIDENT HAZARD. . .
THIS UNIT MUST BE INSTALLED ACCORDING
TO THE MANUFACTURER’S 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 your AJ generator set. Study and follow
the instructions carefully. A well-planned service and
maintenance program will result in longer unit 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 your Onan 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 following).
This information is necessary to identify your
generator set among the many types manufactured
by Onan.
MODEL DESIGNATION
The following typical model number is broken down
into code segments used by Onan.
3.0 AJ - 1 R 16017 S
—I - r- -r - \ - T~
1 2 3 4 5 6
1. Indicates kilowatt rating.
2. Series identification.
3. Voltage code of the generator, 1 = 120 volts.
4. Method of starting:
R—Remote electric starting.
5. Factory code for designating optional equipment,
if any.
6. Specification letter which advances when the
factory makes production modifications.
FUEL REMOTE CONTROL
PUMP PLUG
GOVERNOR
ADJUSTMENT
VIBRATION ISOLATOR
FUEL SOLENOID
SHUTOFF VALVE
FUEL
INLET
GENERATOR
OIL DRAIN
OIL FILL
VACU'FLO
SCROLL
START-STOP
SWITCH
CARBURETOR-
AIR CLEANER
EXHAUST
OUTLET
CIRCUIT BREAKER
GENERATOR
COOLING AIR
IN
BREAKER
BOX
ENGINE
/
DRIP PAN
TYPICAL AJ RECREATIONAL VEHICLE GENERATOR SET
2

SPECIFICATIONS
This manual contains SI metric equivalents that follow immediately in parentheses
after the U.S. customary units of measure.
GENERAL
Nominal Dimensions of Set
Height. 1 5 . 5 0 in. (394 mm)
Width.12 in. (305 mm)
Length. 23.19 in. (589 mm)
Weight.160 lbs. (73 kg)
ENGINE DETAILS
Manufacturer.
Number of Cylinders.
Displacement (cubic inches)
Cylinder Bore.
Piston Stroke.
Compression Ratio.
Engine Speed.
Engine Design.
Starting System.
GENERATOR DETAILS
Manufacturer. OMAN
Design. Revolving Armature, Two Pole, Inherently Regulated, 3600 RPM
Rating (in watts) 60 Hertz. 3000 Watts (3 kW)
Voltage .120
Current Rating .25 Amperes
Phase.Single
Wire. Two
Power Factor..
Cranking Current. 4 0 Amps
Break-away Current. 225 Amps
CAPACITIES AND REQUIREMENTS
Oil Capacity.
Recommended Battery, Electric Start
Battery Charge Rate—Fixed.
Ventilation Requirements (total).
TUNE-UP SPECIFICATIONS
Spark Plug Gap .025 (0.64 mm)
Breaker Point Gap (cold setting).022 (0.56 mm)
Ignition Timing Reference (cold setting).22° BTC
Valve Tappet Adjustment (engine cold)
Intake.011 (0.28 mm)
Exhaust.018 (0.46 mm)
.2 qts. (1.89 litres)
12 Volt, 92 Amp/hr (331.20 kC)
. 1-2 Amps
.50 sq. in. (323 cm^)
. OMAN
.One
. 14.9 (244.16 cm3)
.2-3/4 in. (69.85 mm)
.2-1/2 in. (63.50 mm)
.6.25:1
.3600 RPM
Four Cycle, Air Cooled, L Head
... Exciter Cranking Generator
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 ariseafterthe
unit is installed and subjected to vibration. There are a
few areas that you as the operatorshould be concern¬
ed with. If in doubt aboutany aspect ofyourgenerator
set’s operation or safety, contact your nearest
authorized Onan Service Center. A daily inspection of
your installation should include the following;
• Exhaust
• Fuel System
• Electrical
• Ventilation
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 CONTAIN 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.
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.
Inlet hose connection to fuel filter requires a clamp.
ELECTRICAL
AC Output
Two AC leads. Ml (hot) and M2 (ground), terminate in
generator junction box. These wires should be con¬
nected to distribution box with multistrand wire
enclosed in a flexible conduit. Check all wires (to and
from the generator set) for fraying and loose connec¬
tions. For information on load connections 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.
4

Onan recommends using a separate battery for operation of the
generator set in addition to the regular vehicle starting battery.
Refer to individual installation guide or T-012 for additional
information on battery sharing.
WARNING^ discharged cooling air for com¬
partment heating since it could contain
poisonous exhaust gases.
Grounding: Generator must be effectively bonded to
recreational vehicle chassis.
For additional information on installation contact
your ONAN Service Representative or request In¬
stallation Guide #924-0611.
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
apollcation.
WARNING
ANSI 198.1 AND
recreational vehicles
I Insulation must not reduce the minimum
I clearances as specified In Figure 1 to meet
CSA #946 temperature rise requirements for
Do not terminate poisonous carbon monox¬
ide exhaust gas under vehicle. Direct exhaust
gases away from window and door openings. Keep all openings
above or to the rear of exhaust pipes closed when generator set Is
operating.
WARNING \
WARNING
DO NOT DISCONNECT BATTERY CABLES
FROM BATTERY WHILE GENERATOR SET
IS CRANKING OR RUNNING; SPARKS MAY CAUSE AN EXPLO¬
SION.
WARNING
Mount the battery In a separate compartment
from the set or any spark-producing device to
prevent fire or explosion.
WARNING I
being charged.
Do not smoke while servicing batteries. Lead
acid batteries give off explosive gases while
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.
IMPORTANT: Certain states (particularly California) have state
ordinances pertaining to the type and usage of exhaust
muffler/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 i
ENGINE EXHAUST GAS (CARBON MONOXIDE) IS DEADLY!
Carbon monoxide Is an odorless, colorless gas formed by Incomplete
combustion of hydrocarbon fuels. Carbon monoxide is a dangerous gas that
can cause unconsciousness and is potentially lethal. Some of the symptoms or
signs of carbon monoxide inhalation are:
• Dizziness • Vomiting
• Intense Headache • Muscular Twitching
• Weakness and Sleepiness • Throbbing in Temples
if you experience any of the above symptoms, get out into fresh air
immediately.
The best protection against carbon monoxide inhalation is a regular inspection
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.
5

OPERATION
GENERAL
inspection: Inspect the engine visually before star¬
ting. Check for loose or missing partsorany shipping
damage. The unit may be tilted during operation to
any maximum angle not exceeding vehicle operation
limitations.
Rust inhibitor oil has been placed In the engine combustion
chamber at the factory and may foul the spark plug. If the plug
should foul, remove it and clean thoroughly. Then dry and replace
in engine.
RECOMMENDED FUEL
Use ciean, fresh, unleaded or regular grade gasoline.
Do not use highly leaded premium fuels. Using
unleaded gasoline results in reduced valve and
carbon cleanout maintenance.
If the use of unleaded gasoline is desired, use regular
gasoline for the first 25 hours to allow the rings to seat
well for best performance. Then use unleaded gas¬
oline thereafter.
If regular gasoline is used continually, carbon and
lead deposits must be removed from the cylinder
heads as required because of engine power loss.
Unleaded gasoline may be used safely after lead
deposits have been removed.
Leakage of gasoline in or around the com¬
partment is a definite hazard. The ventilation
system should provide a constant flow of air to expel 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.
OIL
Check oil level daily (see Figure 2). Be sure unit is
level when checking oil. Add oil to top of fill hole if
required. See MAINTENANCE section of this manual
for type of oil, oil viscosity and crankcase capacity.
Do NOT check oil while the generator set is
operating. Hot oil could cause bums by
blowing out of oil fill tube due to crankcase pressure.
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.
OIL DRAIN
FIGURE 2. OIL LEVEL
STOPPING
Push the start-stop switch to the stop position and
hold until unit stops completely.
Automatic Choke
An electric choke provides proper choking for star¬
ting and running the generator set.
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. One half hourat1/2load (with oneairconditioner
running).
2. One half hour at 3/4 load (with one air con¬
ditioner) and approximately 500 watts additional
load.
3. Change crankcase oil after the first 25 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.
BATTERY CHARGING
The battery charge rate is controlled by a fixed value
resistor that allows a trickle charge rate of 1 - 2 amps
under all conditions.
6

SET EXERCISING
Establish an exercise program if unit is not used for
long periods of time. Start and run unit, with a full load
connected if possible, for at least 30 minutes every
week. This exercise program will:
• Lubricate internal engine parts.
• Assure proper starting when set is needed.
• Remove moisture.
• Keep carburetor filled with fuel.
• Bring engine up to operating temperature.
• Recharge battery.
ELECTRICAL OUTPUT
The generator set’s wiring provides for 120 volts, with
the total electrical load not to exceed 25 amperes.
install any outlets between generator
^distribution panel.
120 VOLT. 2 WIRE
UNGROUNDED LOAD WIRE
30 AMP
^ BLACK
120 V (FULL NAMEPLATE RATING)
y WHITE
GROUNDED LOAD WIRE
IM1
GENERATOR LEADS
M2
FIGURE 3. SINGLE-PHASE, “1R” VOLTAGE CODE
GENERATOR CONNECTIONS
POWER REQUIREMENTS FOR APPLIANCES
Appliance or
Tool
Approximate
Running Wattage*
Refrigerator. 600-1000
Electric broom . 200-500
Coffee percolator. 550-700
Electric frying pan. 1000-1350
Hair dryer. 350-500
Electric stove (per element). 350-1000
Electric iron. 500-1200
Radio. 50-200
Electric water heater. 1000-1500
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
Microwave oven.700-1500
' - Starting wattages for motors can be three to four
times more than the approximate running wattages.
HIGH OPERATING TEMPERATURES
1. See thatnothingobstructs 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 TEMPERATURES
1. Use co; • :t SAE oil for temperature 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 richerfuel 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.
EXTREMELY DUSTY OR DIRTY
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 ALTITUDE OPERATION
For operation at altitudes of 2500 feet (775 m) above
sea level, close carburetor main jet adjustment slight¬
ly to maintain proper air-to-fuel 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.
Do not use discharged air from blower scroll
for compartment heating. Poisonous gas
fumes may be present.
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.
warning!
7

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 plug. Spray 1 ounce of rust in¬
hibitor oil (or SAE #10) into the cylinder. (Spray
cans work well for this application.) Turn engine
over by hand at least 2 complete revolutions.
Replace the spark plug.
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. R e m o v e 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. Check to
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.
6. 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.
7. 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.
8. Unit is now ready for service.
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.
8

ADJUSTMENTS
TIMING AND BREAKER POINTS
Ignition points should break contact at 22°BTC (see
Figure 4). Proper 22° BTC timing is obtained by
setting breaker points and checking with a timing
light.
22° BTC timing can be checked at timing hole on the front of blower
housing ("D") or at another timing hole on the side of the blower
housing (“C”) just above the governor adjustment. Breaker point
setting may vary from .017-.024 inch to get proper 22° BTC timing.
1. Turn engine over slowly in a clockwise direction
until the TC mark appears in the middle of the
window “D” (Figure 4). Turn slightly beyond this
point to ensure points are fully open.
2. Remove cover on breaker point box, loosen
screws “A” and turn cam “B” to obtain .020 inch
setting. Use a clean, flat feeler gauge.
3. Retighten screws “A”, replace breaker box cover
and connect a timing light. With unit running and
warmed up, notch should appear In timing
reference hole “C". (If front of blower scroll is
accessible, direct the timing light to small hole
"D”. 22° BTC mark should appear in this hole.)
CARBURETOR
Initial Adjustment
Adjust initially by turning idle and main (load)
adjustment screws gently onto their seats. Then back
off idle screw 1-1/4 turn and main screw 1-1/4 turns.
This adjustment will allow initial starting of the
generator set.
Adjustment
1. Start unit and allow it to warm up.
2. Remove all AC loads from the generator set.
3. Connect a voltmeter to the AC leads or use a plug¬
in voltmeter inserted into one of the receptacles.
Hold governor arm to minimum speed and adjust
the throttle stop screw so voltmeter indicates 75-
80 volts.
4. With voltmeter still connected, hold governor arm
against throttle stop and turn idle adjustment
screw in until voltage drops. Then turn it out until
the highest voltage is obtained. Release governor
arm. Engine should accelerate to governed speed
and become stable.
NOTCH REFERENCE
TIMING HOLE
FIGURE 4. IGNITION AND TIMING ADJUSTMENTS
9

FIGURE 5. CARBURETOR ADJUSTMENTS
5. Connect a full rated load to the generator set.
(Use RV appliances or Onan load test panel.)
6. Adjust main (load) adjustment screw to get the
highest voltage. Remove load and hold governor
arm to minimum speed. Release governor arm
and observe acceleration. If surging occurs at
governed speed, open the main jet slightly. If
surging continues, adjust governor sensitivity.
Some units do not have a main (load) adjustment. Setting is
factory fixed.
ELECTRIC CHOKE
Normal choke setting is 1/8 inch from its fully closed
position at 70° F. If temperature changes occur,
requiring choke adjustment, proceed as follows;
1. Loosen two outer screws at “A” (Figure 6).
2. Turn the cover assembly counterclockwise to
decrease choking (leaner mixture).
3. To increase choking (richer mixture), turn cover
assembly clockwise.
4. Tighten both screws to lock cover in place.
FIGURE 6. ELECTRIC CHOKE ADJUSTMENT
10

GOVERNOR
The governor controls engine speed by opening or
closing the throttle according to the load taken off the
set (Figure 7). The engine speed also determines
voltage and frequency of the generator current.
Before readjusting the governor linkage, check for
binding at the linkage or throttle.
1. With unit stopped, disconnect governor control
rod from hole (E) on throttle shaft. While holding
throttle wide open, adjust length of governor
control rod so center-to-center distance is 1/8
inch. Change governor control rod length by
turning the threaded rod (A) near the ball joint.
When 1 /8 inch distance is reached, reconnect rod
at point E.
2. Run the set with a load to thoroughly warm it up.
3. Connect a voltmeter across the generatoroutput.
With the set operating at no load, adjust the speed
nut (C) until voltmeter reads 126volts. When afull
rated load is applied, voltage should not fall below
110 volts.
4. If voltage falls below 108 volts (with full load),
loosen the hex nuts on sensitivity spring stud and
screw stud (D) inward (clockwise) or recheck
step 1. If voltage is within limits, buttendsto surge
(alternately increases and decreases), turn the
spring stud outward (counterclockwise) until
voltage stabilizes.
5. Retighten nuts on lowerspring stud while holding
stud in position with a screwdriver.
Turning sensitivity stud (D) in or out, usually requires a correspon¬
ding change in speed adjustment nut (C). Table in Figure 7 shows
proper voltage speed and frequency ratings.
r
/
I
\
^ j
/
(
I
1
\
\
\
\
^ .
\ ^
V- 226
FIGURE 7. GOVERNOR ADJUSTMENTS
11

nHDHaH
■■□ ■ ■ a
■■□ ■ ■ □ I
■■ i Shho
■■■ ■ ■ □ I
■ ■ □ iUI
■■ ■ n i
^mmD~
' ' " * V
FUEL SYSTEM
riL
E3C1HH
!« ■ ■■ ■
■ ■ D D B
Broken Valve Spring _
Valve or Valve Seal Leaking
Wrone Bearinc Clearance
COOLING SYSTEM (AIR COOLED)
COOLING SYSTEM (WATER COOLED)

MAINTENANCE
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 dealer.
I WARNING I Always allow generator set to cool off
before performing any maintenance or
installation work on the set. Working on a hot set could cause
severe burns.
PERIODIC MAINTENANCE SCHEDULE
SERVICE THESE ITEMS
AFTER EACH CYCLE OF INDICATED HOURS
8
50 100
200
400
General Inspection
X1
Check Oil Level
X
Check Battery Water Level
x2
Blow Out Generator with Dry Air
x2
Change Crankcase Oil (10W40)
x2
Replace Air Cleaner
x2
Replace Spark Plug—Gap .025"
x3
Clean Crankcase Breather
x2
T une-Up
x4
Check Breaker Points
x4
Check Ignition Timing
x4
Clean Cooling Fins
x2
Remove Carbon & Lead from Cylinder Head
x4
Adjust Tappets
x4
Replace Fuel Filter
X
Check Generator Brushes (Replace if Necessary)
As Required
x1 - Check for exhaust leaks, fuel leaks, proper mounting, etc.
x2 - Perform more often in extremely dusty conditions.
x3 - Replace at beginning of season or every 100 hours.
x4 - For detailed maintenance, contact your nearest authorized Onan Service Center.
All exhaust system connections MUST be checked regularly for any leaks and tightened as
necessary. Do NOT terminate exhaust pipe under vehicle or near any window or door openings.
Inspect the vapor tight seals around all openings made in the set’s compartment for wiring, conduit, etc., to
prevent entrance of any noxious fumes to motor home interior.
WARNING i
13

OIL LEVEL
Check the oil level daily or at least every eight
operating hours. Oil should just start to overflow from
fill hole when crankcase is full.
Check oil when set (or vehicle) is level.
OIL CHANGE
The oil drain valve is located on the side (near the
bottom) of the oil base. Change oil initially at 25
operating hours; change every 50 hours after that.
Extremely dusty conditions require more frequent oil
changes. See Figure 8.
Be sure to fill the crankcase with oil to the “FULL”
mark on the oil level indicator. Use oil with the API
(American Petroleum Institute) designation SE or
SE/CC. Oil should be labeled as having passed MS
Sequence Tests (also known as having passed
ASTMG-1V Sequence Tests). Refer to oil chart for
recommended viscosity and temperature. The
engine’s oil capacity is 2 quarts.
1°C -30 -20 -10 6 10 20 30 40
TEMPERATURE RANGE YOU EXPECT BEFORE NEXT OIL CHANGE
Oil consumption may be higher with a multigrade oil
than a single-grade oil if both oils have comparable
viscosities at 210°F (99°C). Therefore, single grade
oils are generally more desirable unless anticipating a
wide range of temperatures. Use the proper grade oil
for the expected conditions. When adding oil between
FIGURE 8. OIL FILL AND DRAIN
changes, use the same brand as in the crankcase.
Various brands of oil might not be compatible when
mixed.
Use of the same grade and quality of oil as that used in
your recreational vehicle engine is acceptable as long
as unit is serviced regularly and oil meets re¬
quirements shown in chart.
WARNING I check oil while the generator set is
whhhhhJ operating. Hot oil could cause bums by
blowing out of oil fill tube due to crankcase pressure.
FUEL FILTER
An inline fuel filter mounts on inlet side of fuel pump.
Replace at least every 100 hours or when poor
performance is suspected.
When removing or replacing fuel solenoid
) . . . . . . . . 1 always use wrench on hex (A), Figure 9. Do
not exert turning force on B because solenoid will be damaged
internally.
FIGURE 9. INLINE FUEL FILTER
FUEL SOLENOID
Evaporative control systems on late model motor
homes require a positive fuel shutoff valve to prevent
the generator set from flooding when not in use.
AIR CLEANER
Replace air cleaner every 100 hours (sooner in dusty
conditions). Element used is a dry type and requires
no oil. Some dirt can be removed by tapping element
against a flat surface.
AIR CLEANER
COVER ELEMENT
BASE PLATE
FIGURE 10. AIR CLEANER ELEMENT
14

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).
GOVERNOR LINKAGE
Check linkage periodically for freedom of movement.
Disconnect ball joint and clean.
SPARK PLUG
Replace spark plug 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.
COOLING SYSTEM
Check cooling fins and shrouds at least every 200
hours or annually. Remove all foreign material (bugs,
dirt, oil, leaves). Also check generator air inlet and air
outlet for restrictions which can cause overheating.
{ CAUTION 1 operate unit without the cooiing
shrouds instalied; overheating wiii occur
causing engine damage.
BREATHER VALVE
Every 100 hours check the breather valve by removing
breather tube and examining the valve in the
crankcase. The ball-check valve must move freely in
the valve housing chamber. If there is any excessive
accumulation of sludge or dirt, replace the breather
valve.
BREATHER
TUBE
FIGURE 12. CRANKCASE BREATHER
GENERATOR
After approximately 500 hours of operation, remove
the generator brushes and inspect for wear and
scoring. To remove the brushes, unscrew the brush
retainers (Figure 13) and pull the brush and spring
assembly out of the bell housing. The four smaller
retainers hold the slip ring brushes, and the two larger
retainers secure the commutator brushes.
15

WORN NEW
FIGURE 14. BRUSH REPLACEMENT
FIGURE 13. BRUSH LOCATION
The brush faces should have a smooth, shiny surface
to them, with no deep grooves present. If serious
grooves are noted, the commutator and slip rings
should be inspected to determine the cause for
correction purposes. If slip ring and commutator
dressing is required, your nearest Onan Service
Center is best equipped to handle the job.
If brushes appear to be in satisfactory condition, and
are at least 5/8 inch in length, replace them in the
holders from which they were removed. Work the
brushes up and down in the holders to be sure there is
no sticking or binding. If they bind, clean out the
holders with air pressure or a small bristle brush until
the brushes slide freely in the holders. Replace the
brush retainer screws.
If brushes are worn to less than 5/8 inch length,
replace with new brushes (see Figure 14).
Every 500 hours, remove the brushes and blow out the
dust in the generator by blowing compressed air (not
over35 psi) into allthebrush holders with the brushes
removed. Service more often if operating in extremely
dusty conditions.
Replacement brushes are shaped to fit the curvature
of the commutator and seldom need sanding to seat
properly. If sparking does occur, run set at light loads
until new brushes are properly seated.
Never use emery cloth or metal files to seat
brushes. Use only brushes of correct part
number (see your Onan Service Center). Replace brushes in the
same position in holder as they were originally.
EXHAUST SPARK ARRESTER
Exhaust spark arresters are necessary for SAFE
OPERATION. All require periodic clean-out (every 50
to 100 operating hours) to maintain maximum ef¬
ficiency. Some state and federal parks require them.
To clean spark arrester remove pipe plug in bottom of
muffler. Run set under load for 5 minutes. Replace
plug.
ASSEMBLY TORQUES
LB-FT
N*m
Gearcase Cover
10-13 (13.6- 17.6)
Cylinder Head Stud Nuts
(Cold)
24-26
(32.5 - 35.3)
Rear Bearing Plate Screws
15-20
(20.3 - 27.1)
Connecting Rod Bolt
10-12 (13.6 - 16.3)
Flywheel Mounting Screw
35-40
(47.5 - 54.2)
Oil Base Mounting Screws
25-30
(33.9 - 40.7)
Generator Through Stud
Nut
12-15
(16.3 - 20.3)
Armature Through Stud
Nut
25-30
(33.9 - 40.7)
Crankshaft Blower Housing 20-25
(27.1 - 33.9)
Fuel Pump Mounting Screw
10-15 (13.6 - 20.3)
Intake Manifold Mounting
Screw 15-20
(16.3 - 27.1)
Oil Pump Mounting Screw 7-9
(9.5-12.2)
16

CONTROL TROUBLESHOOTING
PROBLEM
PROBABLE CAUSE
REMEDY
FAILS TO CRANK
1. Bad Battery Connection
1 Clean and tighten all battery and cable connections.
2. Low Battery
2A Check specific gravity. Recharge or replace battery if
necessary.
2B Reverse current diode (CR1) may be shorted or open causing
a drain on the battery. R2 may be open.
3. Faulty Start Solenoid (K1)
3 Push start switch. Check start solenoid “SI" terminal voltage to
ground. When battery voltage at start solenoid '‘B + '’ terminal is
present, battery voltage should also appear at "SI ’’ terminal; if
not, replace start solenoid
4. Faulty Start Switch
4. Jumper switch (#3 terminal) to ground. If solenoid energizes,
replace switch.
CRANKS SLOWLY
1. Bad Battery Connection
1 See 1 above (FAILS TO CRANK)
2. Low Battery 2 See 2 above (FAILS TO CRANK)
CRANKS BUT
WONT START
1 Blown Fuse (F2)
1. Replace fuse (F2) on control.
2. Faulty Fuel Solenoid Or
Fuel Pump
On later models, fuel
solenoid is an integral part
of fuel pump.
2, Fuel solenoid must open during cranking and running. Check
by removing steel line from carburetor and crank engine. If
fuel solenoid isopen. fuel will pulsateout of this line. If itdoes
not. the fuel solenoid and fuel pump must be checked
separately to determine defective part
1 WARNING ^ extreme care for this test. Direct fuel
sure area is well ventilated to prevent accumulation of
gasoline fumes.
3. Faulty Ignition
3. Check to see if points open and close during cranking. If they
do not open and close, adjust and set points. Plug and plug
wires must be in good condition Voltage at ignition coil
negative terminal (-) must alternate from +12 volts to zero volts
as points open and close during engine cranking.
4 Inoperative Choke
4 With engine not running, check choke vane movement by
pushing choke lever arm. Choke must be in closed position
with cold engine, and must be free to move against bimetal
spring As engine warms up, bi-metal spring relaxes and allows
choke vane to open fully. The lever will pulsate as engine
warms up. See ADJUSTMENT section
5 Faulty Crank Ignition Relay (K2)
5 Check voltage from relay terminal "4 “ to ground while cranking
unit Battery voltage should appear at this terminal. If not.
check for voltage at relay terminals “I ' and '‘2’ If battery
voltage is present at terminals 1 and 2, but not at 4. replace
relay. If not voltage appears at terminals 1 and 2 on relay while
cranking, check wiring between start solenoid (K1) and crank
ignition relay (K2).
UNIT STARTS, BUT
STOPS IMMEDIATELY
AFTER RELEASING
START SWITCH Si
1 Resistor R1 may be open.
2 Run Ignition Relay K3
3 Low Oil Level
4 S3 Low oil pressure switch may be
defective.
1 Check voltage on both sides of R1 With set running voltage
should be 24-32 volts DC
2 Check voltage on both sides of K3 Should be 12 volts
3 Check oil level. If low or empty, refill to proper level
4 Check S3. Switch should close with set running at 10 lbs.
minimum oil pressure
UNITSRUNSTHEN
STOPS
1. Low Oil Level
1. Check oil level. If low or empty, refill to proper level.
UNITS RUNS BUT
SURGES
1 Stuck Choke
1. See 4 above (CRANKS BUT WONT START)
2 Governor Not Adjusted Properly
2. Readjust governor.
UNITS STOPS
1. Faulty Ignition
1 See 3 above (CRANKS BUT WONT START)
2. Out of Fuel
2. Refill fuel tank.
3. Low Oil Level
3. Check oil level. If low or empty, refill to proper level.
REMOTE RUNNING TIME
METER OR GENERATOR
LAMP INOPERATIVE
1. Blown Fuse (FI)
1 Replace FI fuse on control
i;

A1.Control Assembly
A2.Delux Remote Control
A3.Standard Remote Control
S1.Start-Stop Switch
F1, F2. Fuse (5-amp, 32 Volt)
K1. Start Solenoid
K2.Relay-Crank Ignition
K3.Relay-Run Ignition
E1.Choke - Onan
E2.Spark Plug
E4.Fuel Shut Off Solenoid
T1.Ignition Coil
52 . B r eaker Points Assembly
53 . S w i t ch - Low Oil Pressure
G1. Generator
CB1 .30 Amp Circuit Breaker
R2.Resistor (10-Ohm, 45 Watt)
BT1.Battery - 12 Volt
FIGURE 15. CONTROL SYSTEM SCHEMATIC
18