CJ2A Operation and Care
Manual -- Proper Maintenance
(part 3 -- Engine Electricals,
Fuel and Cooling Systems.)
GENERATOR
The generator is a 35-ampere, two-brush unit which does not require adjustment to increase or decrease output. This is
accomplished by the regulator which limits the current generated to that which is required by the battery. The generator
charging rate, as shown by the ammeter, will be low when the battery is well charged and correspondingly higher as charging
is required.
As a general rule it will not pay an owner, not equipped with specialized test equipment, to undertake generator repairs. There
are some adjustments which may be made without this equipment and which are covered below.
Should the generator stop charging, examine all connections in the charging line to be sure they are clean and tight. Also note
the condition of the commutator and brushes. If the commutator is dirty and discoloured, it can be cleaned by holding a piece
of No. 00 sand-paper against it with the engine running at idle speed. Do not use emery or carborundum cloth.
The brushes must slide freely in their holders and should they be badly worn or oil soaked, they should be replaced. Excessive
arcing between the cummutator and brushes usually indicates incorrect seating of the brushes against the commutator or high
mica insulation between the commutator segments. Incorrect seating may be corrected by drawing a piece of No. 00 sand-
paper around the commutator with the sanded side against the brush. After sanding, blow the carbon dust and sand from the
generator.
Should the above attention fail to make the unit operate satisfactorily, consult your Willys-Overland Dealer.
VOLTAGE REGULATOR
The regulator must be adjusted with great accuracy; hear as well as voltage and amperage must be considered when adjusting
it. Should trouble develop in the regulator either consult a Willys-Overland Dealer or install a new one.
DISTRIBUTOR ASSEMBLY
The distributor delivers the spark to the right cylinder at the right time. The mechanical breaker, built into the distributor, opens
and closes the primary circuit at the exact time for ignition. See Fig. 7 on the first page of Proper Maintenance.
The distributor cap should be kept clean for efficient operation. It should be inspected periodically for cracks, carbon runners,
evidence of arcing and badly corroded high tension terminals. If any of these conditions exist, the cap should be replaced.
Inspect the distributor rotor for cracks or evidence of excessive burning at the end of the metal strip. After a rotor has had
normal use, the end of the metal strip will become burned. If burning is found on top of the rotor, it indicates the rotor is too
short and should be replaced. Usually then this condition is found, the distributor cap segment will be burned on the horizontal
face and the cap should also be replaced.
The distributor contact points should be kept clean and not burned or pitted. The contact gap should be set at .020" (0.51 mm.).
When making adjustments, be sure that the fibre block in the breaker arm rests on one of the high points of the cam. Adjust the
points by loosening the lock screw and turning the eccentric head screw. Recheck the gap after tightening the lock screw.
Should new contact points be installed they should be aligned so as to make contact at the centre of the contact surfaces. Bend
the stationary contact bracket to secure correct alignment and then recheck the gap.
SPARK PLUGS
Keep spark plug porcelains clean. Dirty porcelains will cause hard engine starting and poor operation especially in damp
weather.
The spark plug electrode gap should be set at .030" (0.76 mm.). Too wide gap will cause misfiring, especially at high speeds
and when operating with open throttle, while a small gap causes poor idling. Uniform gap setting assures smooth engine
operation.
It is recommended that spark plugs be replaced at intervals of each 10,000 miles of service for, because of erosion, the spark
loses intensity.
STARTING MOTOR
The starting motor requires little attention except regular lubrication. It is a standard three-bushing type motor with right-hand
type Bendix spring.
It is not advisable to lubricate the Bendix drive shaft. In use dirt and dust will cling to the Bendix shaft, if lubricated. In time
the shaft may become gummy, preventing engagement of the Bendix pinion with the fly-wheel ring gear, especially in cold
weather. Should the starting motor turn without turning the engine, remove the motor and wash the Bendix assembly
thoroughly with cleaning solution.