Onan CCK Series Instruction Manual

Qnan
ELECTRIC
POWER PLANTS
FOR RECREATIONAL VEHICLES
SERIES
CCK
ONAN
1400 73RD AVENUE N.E. • MINNEAPOLIS, MINNESOTA 55432
4 DIVISION Of ONAN CO/tPOHAriON
N.Y. INTERNATIONAL OFFICE: Empire State Bldg,
927-310
6AP71

GENERAL INFORMATION
This manual includes instructims for the installation,
operation, and maintenance of the CCK electric
generating plants used in mobile applications. Identify
the model by referring to the MODEL AND SPECIFI¬
CATION NUMBER as shown on the ONAN nameplate.
Electrical characteristics are shown on the lower
portion of the nameplate.
How to interpret MODEL and SPEC NO.
5.0CCK . lR/6000 P
1 2 3 4
1. Factory code for general identification.
2. Specific type;
M-MANUAL. Manually cranked. For permanent
or portable installations.
R-REMOTE. Electric starting. For permanent
installation can be connected to optional accessory
equipment for remote or automatic control of
starting and stopping.
3. Factory code for optional equipment.
4. Specification (Spec) letter (advances when factory
makes production modifications).
Electric plants ate given a complete running test under
various load conditions and thoroughly checked before
leaving the factory. Inspect the plant closely for loose
or missing parts and any damage which may have
occurred in shipment. Tighten loose parts, replace
missing parts and repair any damage before putting
plant in operation.
TABLE OF CONTENTS
title page
General Information. 1
Specifications. 2
Troubleshooting. 3
Installation. 4
Operation. g
Adjustments. 10
Service and Maintenance.J5
Parts Catalog.jg
TYPICAL CCK FOR MOBILE APPLICATIONS

SPECIFICATIONS
ENGINE
Number of Cylinders.2
Cubic Inch Displacement.49.8
Cylinder Bore..3 1/4
Piston Stroke..3
Compression Ratio...5.5 ; l
RPM...1800
Ignition Type.Battery
Battery Voltage.12
Battery Size '
SAE Group IH.2 in series
SAE Rating-20Hour (nominal).105amp/hr
Battery Charge Rate (maximum).6 amp
Ventilation Required (cfm)
Engine. 750 cfm
Generator . . V .75 cfm
Combustion.32 cfm
GENERATOR
AC Voltage Regulation. . ± 4 %
AC Frequency Regulation.5%
Rating (output in watts) 4.0 CCK 5.0 CCK
60 Hertz AC Mobile Service. . 4000 5000
PLANT DIMENSIONS
Model 4.0 CCK. Single Phase. 2 Wire
Length. 29 3/8
Width. .20 1/2
Height . .22
Weight .339
Model 5.0 CCK, Single Phase, 2 Wire
Length. 32 7/8
Width.20 1/2
Height . .22
Weight.397
FEATURES
Battery Ignition /
Exciter Cranking
Rotating Exciter
Revolving Armature
Output Rated at Unity Power Factor Load
NOTE: Hertz is a unit of frequency equal to one cycle per second.

TROUBLE-SHOOTING GUIDE

INSTALLATION
(
If the mobile electric power plant is to operate properly,
it must be correctly installed. This manual gives some
of the more important aspects of installation. For
more details, a Technical Bulletin (T-OIS) is available
from Onan.
Ventilation is the most important factor to be consid¬
ered. The unit must have enough cooling air to operate
safely and efficiently. The heated air must be disposed
of to keep the engine from overheating and losing
power.
For the CCK electric plant running at 1800 rpm, the
——unt of air discharged is 750 efm. The minimum
free air inlet with no filter or restriction is 140 sq. in.
Onan Vacu-Flo cooled units are specifically designed
for mounting in small compartments (where proper
cooling is difficult) and are equipped to provide suf¬
ficient cooling air and adequate disposition of heated
air. With this type of cooling, a centrifugal fan in a
scroll housing pulls cooling air into the compartment
and over the cooling fins and surfaces of the engine.
Heated air is expelled through a single discharge and
away from the unit and installation area.
TYPICAL -SLIDE OUT " TRAY FOR COMPARTMENT MOUNTING
EXHAUST
CONNECTION
BEVEL MUST BE
BACK PAR ENOUGH
SO AS NOT TO LET
TRAY BOCK WHEN
IN POSITION.

LOCATION
The compartment itself should be of vapor tight design
and completely independent of living quarters. A sheet
metal covered compartment may be readily sealed and
lends itself easily to treatment. The plant may have
to be removed for service, so make the door large
enough to facilitate removal of the unit.
The compartment location is determined by physical
size, access opening and most important, best mounting
support. Allow 2" clearance on all sides of the plant
for rocking on mounts.
POSITIONING
The following should be considered for accessibility
when mounting the unit in a compartment. (Position
so operating instructions and nameplate are visible
and/or install an accessible nameplate, data decal
or sticker.)
1. Make air discharge duct as short as possible.
Position so exhaust heated ait is not drawn into
cool air inlet.
2. Ait cleaner should be easy to remove and service.
3. Battery or batteries roust be accessible for service.
4. Oil fill tube cap should be easy to reach.
5. The control box switch should be visible.
6. Provide space for muffler.
7. Oil drain should be readily accessible.
8. Cylinder head readily accessible for service.
9. Rope start sheave should be accessible.
MOUNTING
The best method of mounting is to attach the plant
to a mounting platform using Onan vibration isolators.
See Figure 2. The vibration isolators must be properly
installed to minimize vibration. The Onan mounts
are a “fail-safe" type with mounting bolts that prevent
the unit from breaking loose if the mounts are damaged.
The mounting base should be fastened directly to the
supporting frame. Channel, box or angle iron can be
used for a mounting base frame. This will provide
the greatest support plus a base sealed against ait,
dirt and sound. Do not use sheet metal or thin plate
without a supporting frame. Plywood of sufficient
thickness for strength can be used, but unless it is
suitably sealed, it is vulnerable to climatic elements,
will tend to become oil soaked, and is not fireproof.
The supporting base or platform must be strong enough
to withstand the shock from sharp turns, bumps, holes,
etc. which accompany mobile applications. Brace the
mounting platform to eliminate any chance of the
platform bowing or bending.
It is desirable to mount the unit on a pullout tray to
facilitate service and repair. The load wires, control
wires and fuel lines must have enough slack and be
flexible so the unit can slide out without disconnecting
them. When using a pull-out tray, pipe the exhaust
gases into the air outlet. The air outlet duct may face
the botttxn, side or top of the enclosure, depending
on bow the unit is installed.
FUfil. SUPPLY (GASOLINE)
Install a separate fuel tank for the unit. If the plant
has to be connected to the vehicle supply tank, do
not tee off the vehicle supply line. The generating
unit must have a separate fuel line because the more
powerful vehicle fuel pump will starve the generating
unit for gasoline.
FUEL LINES
Use annealed copper or seamless steel tubing and
flared connections. Run fuel lines, at the top level
of the tank to a point as close to the engine as pos¬
sible, to reduce the danger of fuel siphoning out of
the tank if the line should break. Install lines so
they are accessible at all times and protected from
mechanical injury. Use nonferrous metal straps,
without sharp edges, to secure the fuel lines.
EXHAUST
If the unit is permanently mounted, pipe the exhaust
to a muffler mounted under the floor. If the unit is
mounted on a slide-out tray, vent the exhaust through
the air discharge duct. Flexible exhaust tubing (used
between the unit and the muffler) absorbs unit vibration.
If the exhaust line passes through a flamiSable floor
or partition, insulate with asbestos backed metal
collars where it passes through these barriers. Exhaust
lines may be asbestos wrapped to reduce heat radiation
within the compartment. However, care should be taken
to see that flexible exhaust sections that are wrapped
still retain their flexibility.
When installing mufflers, other than those supplied
with plant or if the exhaust system is excessively
complicated, the exhaust back pressure should be
checked. Exhaust back pressure at rated load, mea-

sured at the exhaust manifold, should not exceed
2 in. Hg. (Mercury column). Where a tapped hole is
not provided, the manifold and/or a pipe coupling may
be drilled and tapped. After measurement is made,
plug the hole with an ordinary pipe plug.
I i^aRNINO \ discharged Vacu-FIo air
for heatmg since it may contain
carbon monoxide or other poisortoua gases.
BATTERY CONNECTION
Connect the-positive battery cable to the start solenoid
(located in the control box). See Figures. Connect
the negative battery cable to a good ground on the
generator.
Do not disconnect the starting bat-
terfes while the engine is running.
The resulting overvoltage will damage the electric
choke and other control components.
In mobile applications where the generator is normally
operated in ambient temperatures above 0°F and the
battery is kept charged by frequent tunning of the
unit, a single 12 volt battery of 72amp/hr capacity
minimum is sufficient.
WIRING
All wiring must meet applicable local electrical codes.
Wires must be of adequate size, properly insulated
and supported in an approved manner. Have a qualified
electrician install and inspect the wiring.
Mount switches and controls securely to prevent damage
from vibration and road shocks. All switches should
be vibration proof to prevent accidental opening or
closing while the vehicle is in motion. Protect load
circuits and generator output circuits by proper size
fuses or circuit breakers to prevent severe overload
conditions from damaging the generator.
Some special precautions must be taken when installing
AC load wires to Onan electric plants if the plant is
single phase but has 3 output wires (120/240 volt
output). Balance the 120 volt loads between the two
legs of the generator windings. This means connecting
half of the vehicle's 120volt load to each leg of (he
generator output. The average running load would be
approximately equal for each side of the generator
output. Attempting to take the full load off only one
leg couto damage the generator output windings.
Connect any 240 volt load across both windings.

To control the plant from several locations, install
separate, switches and wire them in parallel (Figure 5).
Any number of switches may be used.

OPERATION
BEFORE STARTING
Be sure the crankcase has been filled with oil to the
"FULL” mark on the oil level indicator. Refer to the
Maintenance Section for the recommended oil changes
and complete lubricating oil recommendations.
ELECTRIC STARTING
Push the START-STOP switch to its "START” posi¬
tion. Release the switch as soon as the engine starts.
If the engine fails to start at first try, inhibitor oil
used at the factory may have fouled the spark plug.
Remove the plug, 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.
If the battery charge condition is too low to crank
the engine, the plant can be started manually. Set
the control box switch (located inside the control
box) to its manusl start position. Pull the rope with
a fast, steady pull to crank the engine. Do not jerk.
After starting, return the control box switch to the
electric start position to avoid discharging the battery.
APPLYING LOAD
If practical, allow plant to warm up before connecting
a heavy load. Continuous generator overloading may
cause high operating temperatures that can damage
the wlDdings. Keep the load within nameplate rating.
STOPPING
1. Push start-stop switch to stop position.
2. Release switch when plant stops. If stop circuit
fails, close fuel valve.
BREAK-IN PROCEDURE
Controlled break-in with the proper oil and a con¬
scientiously applied maintenance program will help
to assure satisfactory service from your Onan electric
plant.
When operating engine for the first time, use the
following sequence using MS/DG oil:
1. One half hour at 1/2 load.
2. One half hour at 3/4 load.
3. Full load.
4. Change crankcase oil after the first 50 hours of
operation.
BATTERY CHARGING
The battery charge rate is automatically controlled
by a voltage regulator. The high charge rate was set
at the factory for average operating conditions. If
frequent starts and short operating periods require
an increased charge rate, adjust by moving the slide
clip on the adjustable resistor in the control box. Do
not exceed Samps.
INFREQUENT SERVICE
If the plant is used infrequently, extended shutdown
periods can result in difficult starting. Run the plant
at least 30 minutes every week to eliminate hard
starting.
HIGH TEMPERATURES
1. See that nothing obstructs air flow to and from
the plant.
2. Keep cooling fins clean. Air housing should be
properly installed and undamaged.
3. Kee|^ ignition timing properly adjusted.
LOW TEMPERATURES
1. Use correct SAE No. oil for temperature conditions.
Change oil only when engine is warm. If an
unexpected temperature drop causes an emergency,
move the plant to a warm location or apply heat
externally.
2. Use fresh, standard grade gasoline. Protect
against moisture condensation. Below 0°F 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 air flow, but use care to
avoid overheating.
OUT-OF-SERVICE PROTECTION
Protect a plant that is to be out-of-service (or more
than 30 days as follows:
1. Run the plant until thoroughly warm.
2. Turn off fuel supply and run until plant stops.
3. Drain oil from oil base while still warm. Refill
and attach a warning tag stating oil viscosity used.
4. Remove each spark plug. Pour loz. (two table¬
spoons) of rust inhibitor (or SAE #50 oil) into
each cylinder. Crank engine slowly (byi-hand)
several times. Install spark plugs.
5. Service air cleaner.
6. Clean governor linkage and protect by wrapping
with a clean cloth.
7. Plug exhaust outlet to prevent entrance of moisture,
dirt, bugs, etc.
8. Wipe generator brushes, slip rings, etc. Do not
apply lubricant or preservative.
9. Wipe entire unit. Coat rustable parts with a light
film of grease or oil.
10. I f battery is used, disconnect and follow standard
battery storage procedure.

operate start switch
Energizes start solenoid
Solenoid contacts close
Current fed to generator Current fed through voltage dropping
Current
fed to electric
series field, cranks
resistor energizes stop relay and
choke operates car-
engine.
closes its contacts.
buretor choke.
I
Battery current fed to ignition coil through the
stop relay contacts and the resistor.
Engine starts
I Operate start switch until generator speed builds up.
Release start switch.
j
Generator DC current pro¬
duced.
AC output current produced and fed
to load.
1 ■ ‘ J_ 1^:_ j _
Start solenoid de- Takes over energizing
Recharges Takes over operating
energized. of stop relay.
battery.
of choke.
1
The charge rate is high when the When the battery becomes fully
battery is not fully charged DC
charged, the voltage regulator re-
current passes through both the
moves the adjustable resistor from
adjustable resistor and the fixed
from the circuit and current
resistor which are paralleled by
passes through the fixed resistor
the closed contacts of the two-
step voltage regulator.
only.
1
^ L
1 Exciter voltage closes the reverse current relay, feeding current into the battery.
DUST AND DIRT
1. Keep plant 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 commutator.
Do not remove normal (dark brown) film. Do not
polish.
HIGH ALTITUDE
For operation at altitudes of 2500 feet abc^e sea level,
close carburetor main jet adjustment slightly to maintain
proper air-to-fuel ratio (refer to the Adjustments Sec¬
tion). Maximum power will be reduced approximately
4% for each 1000 feet above sea level, after the first
1000 feet.

ADJUSTMENTS
(
It is necessary to move the control box to obtain
access to the breaker point box. After removing one
screw (see Figure 7) the control box can be moved
aside to provide ample room to service the breaker
points.
If the points are only slightly burned, dress them
smooth with a file or fine stone. -Measure the gap with
a thickness gauge. Set the gap at .020". Crank the
engine to fully open the breaker points (1/4 turn after
t^ center). Loosen and move the stationary contact
to correct the gap at full separation. Secure the points
and check for correct gap.
Ignition points should break contact just when the
white timing mark on the flywheel aligns with the
19“’ mark on the timing bracket. Check the timing
through the opening in the side of the blower housing
after removing the plug button. See Figure 7. Final
timing is conected by shifting the breaker point box
on its mounting and using a timing light. If specified
timing cannot be obtained by positioning the breaker
point box, check to be sure the timing marks on the
gears are aligned.
FIG. 7. TIMING MARK LOCATION

CARBURETOR, GASOLINE
The carburetor has an adjustable idling jet and an
adjustable main jet. If the engine runs unevenly at
half or full load due to faulty carburetion, the main
adjusting needle requires adjustment. The idle ad¬
justment needle normally requires little attention
other than a periodic cleaning. A hunting condition
(alternate increase and decrease in engine speed) at
no load can sometimes be adjusted by an idle jet
adjustment. Make all adjustments with the engine
at normal operating temperature.
To adjust the main jet, connect a full or nearly full
load to the engitte. Turn the main adjusting needle
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 the engine tuns smoothly at
full power and speed. If the engine develops a hunting
condition try correcting by opening the main adjusting
needle a little more. Do not open more than 1/2 turn
beyond the maximum point of power. If this does not
correct the condition, adjust the sensitivity of the
governor.
Make the idle jet adjustment with no load connected
to the engine. Turn the needle in until the engine
loses considerable speed. Then turn it out until the
engine runs smoothly.
SISSON CHOKE
This choke should not require any seasonal readjust¬
ment. If adjustment becomes necessary, pull choke
lever up and insert a 1/16" diameter rod through
shaft hole (opposite end from lever) and engage rod
in notch of mounting flange, to lock shaft in place.
Loosen the choke lever clamp screw. With air inlet
removed, adjust choke lever so carburetor choke plate
is completely closed, or not more than 5/16" open.
Tighten choke lever clamp screw and remove locking
rod from shaft.
THERMO-MAGNETIC CHOKE (OPTIONAL)
This choke uses a strip heating element and a heat
sensitive bimetal spring to control the choke plate
position. In addition to this, a solenoid is actuated
during engine cranking, closing the choke all or part
way, depending on ambient temperature. The bimetal
is factory set to position the choke to the proper
opening under any ambient condition. ^
If adjustment of the bimetal is needed, it must be
made at ambient temperature. Do not attempt adjust¬
ments until the engine has been shut down for at least
one hour. Loosen the screw which secures the choke
body assembly (see Figure 10). Rotating the choke
body clockwise tichens and counterclockwise leans
the choking effect. For ambient temperatures below
60‘^F the choke should be opened 1/8" with the sole¬
noid not engaged. Tighten the screw that secures
the choke body.

ELECTRIC CHOKE
If extremes in starting temperatures require a readjust*
ment of the choke, loosen slightly the two cover retain¬
ing screws. For less choking action, turn the covet
assembly a few degrees in a clockwise direction. For
more choking action, turn counterclockwise. Retighten
the covet screws.
GOVERNOR
Before making fittal governor adjustments, run the
plant about 15 minutes under light load to teach 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 ate decreased. An accurate voltmeter
or frequency meter (preferably both) should be con¬
nected to the generator output in order to correctly
adjust the governor. A small speed drop not noticeable
without instruments will result in an objectionable
voltage drop. The engine speed can be checked with
a tachometer.
A bindihg in the bearings of the governor shaft, in the
ball joint, or in the carburetor throttle assembly will
cause 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 conect the trouble.
1. Adjust the carburetor main jet for the best fuel
mixture while operating the plant with a full rated
load connected.
2. Adjust the carburetor idle needle with no load
connected.
3. Adjust the length of the governor linkage and
check linkage and throttle shaft for binding or
excessive looseness.
4. Adjust the governor spring tension for rated speed
at no load operation with booster disconnected
(or held inoperative).
5. Adjust the governor sensitivity. g
6. Recheck the speed adjustment.
7. Set the carburetor throttle stop screw.
8. Set the vacuum speed booster.
GOVERNOR AND BOOSTER
The governor and booster control the speed of the
engine. A speed adjustment includes adjusting both
devices (Figure 12).

VOLTAGE CHART
FOR CHECKING GOVERNOR REGULATION
SPEED CHART
FOR CHECKING GOVERNOR REGULATION
Maximum No Load Speed
RPM
1920
Nertz (Current Frequency)
64
Minimum Full Load Speed
Without Booster
RPM 1710
Hertz
57
Maximum Speed Drop from No
Load Operation to Pull Load
Operation
RPM
90
Hertz
Preferred Speed Regulation No
Load to Full Load Operation
RPM
1830-1770
Hertz
61-59
Preferred Speed Spread
RPM
60
Hertz
2
LINKAGE
The engine starts at wide open throttle. The length
of the linkage connecting the governor arm to the
throttle shaft and lever is adjusted by rotating the
ball joint. Adjust this length so that with the engine
stopped and tension on the governor spring, the stop
on the carburetor throttle lever just contacts the
underside of the carburetor bowl. This setting allows
immediate control by the governor after starting. It
also synchronizes travel of the governor arm and the
throttle shaft.
SPEED ADJUSTMENT
With the warmed'Up plant operating at no load, and
with the booster external spring disconnected (or
otherwise held inactive), adjust the tension of the
governor spring. Refer to Voltage Chart and the Speed
Chart and select the column which corresponds to the
nameplate of the plant in question. Turn the speed
adjusting nut to obtain a voltage and speed reading
within the limits shown.
SENSITIVITY ADJUSTMENT
Refer to the Governor Adjustment illustration, and to
the Voltage and Speed Charts. Check the voltage and
speed, first with no load connected and again with a
full load. Adjust the sensitivity so as to give the
closest regulation (least speed and voltage difference
between no load and full load) without causing a
hunting condition.
To increase sensitivity (closer regulation), shift the
adjusting clip toward the governor shaft.
An adjustment for too much sensitivity will cause
alternate increase and decrease of engine speed
(hunting).
To decrease sensitivity, shift the adjusting clip toward
the outer end of the governor arm. Too little sensi¬
tivity 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) ad¬
justment.
SPEED BOOSTER
After satisfactrxy performance under various loads
has been attained by governor adjustments without
the booster, the booster can be connected. Connect
the booster external spring to the bracket on the
governor link (rod). With the plant operating at no
load, slide the bracket on the governor link just to
the position where there is no tension on^the external
spring (Figure 12).
Apply a full rated electrical load to the generator.
The output voltage should stabilize at nearly the same
reading for full load as for no load operation. The
speed may remain about the same or increase when
the load is applied, resulting in a frequency 1 or 2 hertz
higho' than the no load frequency (1 hertz is equal to

30rpm for a 4 pole generator). If the rise in frequency
is more than 2 hertz, lessen the internal spring tension.
If there is a drop in the frequency, increase the booster
internal sprite tension. To increase the tension, pull
out on the spring bracket and more the pin to a different
hole.
With the booster disconnected, a maximum drop of
3 hertz from no load to full load is normal. With the
booster in operation, a maximum increase of 2 hertz
from no load to full load is normal. A drop of 1 hertz
at 1/4 load is permissible, giving an overall spread
of 3hertz, maximum.
The effect of the booster is limited by the general
condition of the engine. The booster cannot compen¬
sate for a loss in engine vacuum caused by leaky
valves, worn piston rings, etc.
FIG. 12. GOVERNOR AND SPEED BOOSTER

SERVICE AND MAINTENANCE
CRANKCASE OIL
Fill to the “F” mark on the oil level dipstick. Use a
good quality detergent oil that meets the API (American
Petroleum Institute) service designations SD or SD/CC.
Oil should be labeled as having passed the MS sequence
tests (also known as the ASTM G-IV sequence tests)
and the MIL*L*2104B tests. Use the proper SAE number
of oil for the expected temperature conditions. Do not
mix brands or grades. Extremely dusty or low tempera*
tore conditions require oil change at 50 hours. Oil
capacity is 4 U.S. quarts.
FIG. 13. OIL LEVEL INDICATOft
CRANKCASE BREATHER
Lift off rubber breather cap. Carefully pry valve from
cap. Otherwise press hard with both thumbs on top
of the cap and fingers below to release valve from
rubber cap. Wash this fabric flapper type check valve
in a suitable solvent. Dry and install. Position
perforated disc toward engine.
AIR CLEANER
Clean screen and cup in a suitable solvent. Refill to
level indicated on cup. Use the same type of oil as
used in crankcase. Refer to Operator Maintenance
Schedule for further recommendatioi6.
FIG. IS. AIR CLEANER
FIG. 14. CRANKCASE BREATHER FIG. I. SPARK PLUG GAP

SPEED BOOSTER
Use a fine wire to clean the sraall 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
plant 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
FIG. 17. VACUUM SPEED BOOSTER
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 18. Also
inspect the linkage for binding, excessive slack and
wear.
FUEL SEDIMENT
Empty carburetor and fuel filter (strainer) bowls of
any accumulated sediment. Clean filter screen thor¬
oughly. Reassemble and check for leaks.
GASOLINE FUEL
Use regular grade automobile gasoline. Do not use
highly leaded premium types.
I WARNINO I Never fill the tank when the engine
is running. Leave some tank space
for fuel expansion.
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 thoroughly familiar
with the operation of electric generating equipment.
BRUSH REPLACEMENT
Install new commutator brushes when the old ones are
worn to 5/8" in length. The collector ring brush may
be used until worn to 5/16" in length. It is not neces¬
sary to remove the brush rig to install new brushes.
Remove the end cover to expose the brush rig. Brushes
and leads are then easily accessible. New brushes
are shaped to fit and seldom need sanding to seat
prc^erly. Always use the correct brush as listed in
the parts list, never substitute a brush which may
appear to be the same, but may have different electrical
characteristics. Be sure to tighten the brush lead
terminal nuts. If some brush sparking occurs after
replacing brushes, run the plant at a light load until
tlie 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 cleaning with
a dry, lint free cloth is usually sufficient. Very fine
sandpaper (#00) may be used to remove slight rough¬
ness. Use only light pressure on the sandpaper, while
the plant is operating. Do not use emery or carborundum
paper or cloth. Clean out all carbon dust from the
generator.
16

MAINTENANCE SCHEDULE
Use factory recommerjded maintenance schedule (based
on favorable operating conditions) to serve as a guide
to get long and efficient plant life. Neglecting routine
maintenance can result in failure or permanent damage
to the plant. Maintenance is divided into two cate¬
gories:
1. Operator maintenance — performed by the operator.
2. Critical maintenance — performed by qualified
service personnel (Onan dealer).
OPERATOR MAINTENANCE SCHEDULE
XI Perform more ofcen in extremely dusty cendUions.
For any abnormalities in operation, unusual noises
from engine or generator, loss of power, overheating,
etc., contact your ONAN dealer.
CRITICAL MAINTENANCE SCHEDULE
MAINTENANCE ITEMS
OPERATIONAL HOURS
Cf<eck Breaker Poin
Check Brushes
Remove Carbon & Lead
Check Valve Clearance
Clean Carburetor
Clean Generator
Remove & Clean Oil Base
General Overhaul
xl Perform more ofcen In extremely dusty conditions.
^‘x2 Replace collector ring brushes when worn to 5/16'' or
less. Replace commutator brushes when worn to S/s"
CLEARANCES
Spark Plug Gap 0.025"
BOLT TORQUES FT.-LB.
Spark Plu(s 25-30
Cylinder Head 29-31
Oil Base Mounting 43-48
Tappets (Intake & Exhaust) O.OIO" to 0.012"
Ignition Breaker Points Gap 0.020"
Ignition Timing I9°BTC
17

PARTS CATALOG
INSTRUCTIONS FOR ORDERING REPAIR PARTS
Fot parts oi service, contact the dealer froo whom you purchased this equipment or refer to your Nearest Autho¬
rized Onan Parts and Service Center.
To avoid errors or delay in filling your parts order, please furnish all information requested.
Always refer to the nameplate on your unit:
1. A lways give the MODEL and SPEC NO. and SERIAL NO.
For handy reference, insert YOUR engine
nameplste information in the spaces above.
2. Do not order by reference number or group number, always use part number artd description.
3. Give the part number, description and quantity needed of each item. If an older part cannot be identified,
return the part prepaid to your dealer or nearest AUTHORIZED SERVICE STATION. Print your name and
address plainly on the package. Write a letter to the same address stating the reason for returning the part.
4. State definite shipping instructions. Any claim for loss or damage to your unit in transit should be filed
promptly against the transportation company making the delivery. Shipments are complete unless the packing
list indicates items are back ordered. ^
Prices are purposely omitted from this Parts Catalog due to the confusion resulting from fluctuating costs, import
duties, sales taxes, exchange rates, etc.
For current parts prices, consult your Onan Dealer, Distributor or Parts and Service Center.
"En esta lista de partes los precios se omiten de proposito, ya que bastante confusion resulto de fluctuaciones
de los precios, derechos aduanales, impuestos de venta, cambios extranjeros, etc."
Consiga los precios vigentes de su distribuidor de productos "ONAN”.

This catalog applies to the standard CCK Mobile Plants as listed below. Parts are arranged in groups of related
items. Each illustrated part is identified by a reference number corresponding to the same reference number below
the illustration. Parts illustrations are typical. Using the Model and Spec No. from the plant nameplate, select
the Parts Key No. (1, 2, etc. in the last column) that applies to your plant Model and Spec No. This Parts Key
No. represents parts that differ between models. Unless otherwise mentioned in the description, parts are inter¬
changeable between models. Right and left plant sides are determined by facing the engine end (front)(rf the plant.
PLANT DATA TABLE
ELECTRICAL DATA
WATTS* WIRE PHASE
4.0CCK-IR/1
REMOTE 4000 120 60 1
4.0CCK-3R/ 1 REMOTE 4000
120/240
60
1
1
4.0CCK-3CR/' t REMOTE
4000 120/240 60
t
1
5.0CCK-IR/4
REMOTE
sooo 120
60 2 1
5.0CCK-3R/ i
REMOTE sooo l20/^f40 60
3
1
2
5.0CCK-3CR/ i
REMOTE sooo 120/240 60
t
1
* • Maximum standby ratint is shown. Continuous rating also shown on nameplate.
1- The Specification Letter advances (A to B, B to C. etc.) with manufacturing changes,
f - These generators have 4 load wires which are reconnectible for 120 volt 2wlre service, or 240 volt 2wlre
service, or 120/240volt 3wire service.
*- New model designations shown, begin during 1969. Previous designations did net use a decimal in the
KW rating. EXAMPLE: 4.0CCK was formerly 4CCK and 5.0CCK was formerly 5CCK. Also previously
a V was used in the model to designate vaeu-flo cooling.
NOTE: Harts is a unit of frequency equal to orw cycle per second.