Section IX. MAINTENANCE OF ELECTRICAL SYSTEM

dust and dirt to enter the engine, causing rapid

positions, screw the ball joint on or off the control

engine wear.

rod until you can aline the right angle stud on the

(2) When you connect the choke control wire

ball joint fitting with the top hole on the governor

to the carburetor, adjust it so that the choke lever

lever, then screw fitting in two additional turns.

can move through its full operating range as the

d. Insert ball joint stud into the top hole in the

choke control on the instrument panel is operated.

governor lever, install and tighten lock nuts.

( 3 ) Adjust the throttle linkage from the

e. With the governor lever pushed toward the

governor as directed in paragraph 4-21.

carburetor as far as it will go, be sure you have

approximately 1/16-inch clearance between the

4-21. Governor Adjustment

throttle lever and the stop pin on the carburetor. If

To insure proper operation of the governor and

the clearance is not correct, you can adjust it by

carburetor, refer to figure 4-6 and adjust the

turning control lever ball joint farther on or off

throttle linkage as follows:

control rod; refer to above subparagraph c.

NOTE

f. To adjust the maximum operating speed of the

Before you adjust the throttle linkage, you must make

engine you must be sure the spring is hooked into

sure the idle speed adjusting screw is set for the

the proper hole in the governor lever. Hook the

proper idle speed.

spring in hole No. 11 (fig. 4-6), the eleventh hole up

a. Disconnect the control rod ball joint from the

from the lever shaft. There are 12 spring mounting

governor lever.

holes. With engine operating and throttle fully

b. Push the control rod toward the carburetor as

open, the full-load speed will be approximately

far as it will go, causing the throttle to open fully.

2350 rpm.

c. Move the governor lever as far as possible in

the same direction. Holding both parts in these

Section IX. MAINTENANCE OF ELECTRICAL SYSTEM

instructions may damage the alternator

4-22. Description

rectifiers, voltage regulator, and wiring.

a. Battery. T h e electrical system includes the

c. Magneto. The magneto is timed to the engine

battery box which houses one 24-volt, lead-acid-

and is driven by the idler gear. Voltage induced by

type storage battery to power the 24-volt, negative

the magneto coils is applied to the spark plug of the

ground electrical system. Battery output is used to

appropriate cylinder at the required instant by the

energize the electrical starting motor to start the

distributor rotor in the magneto. The breaker

engine. The battery charge is partially depleted as

points open at the correct instant to assure a hot

the engine is started and is restored by the battery

spark to the spark plug at this time. The magneto

charging system consisting of the alternator and

also contains automatic spark advance provisions

voltage regulator.

so that the spark will occur sooner during high

b. Alternator and Regulator. T h e f l y w h e e l

speed operation. This is necessary for smooth

alternator is a permanent-magnet type and has no

engine performance.

brushes, commutator, belts, or adjustments. The

d. Spark Plugs. Four radio-shielded spark plugs

alternator output is controlled through the voltage

receive the spark from the magneto and ignite the

regulator, depending upon the state of battery

fuel-air mixture in the appropriate cylinder. The

charge. When the battery charge is low, the voltage

firing order of the cylinders is 1-3-4-2. When you

regulator increases the output of the alternator;

view the engine from the flywheel end, the number

when the battery charge is normal, the output of the

1 cylinder is the one nearest the flywheel on the left

alternator decreases to near zero.

bank of cylinders. The number 3 cylinder is the

CAUTION

other cylinder in this bank. The number 2 cylinder

Though this engine is equipped with a

is the one nearest the flywheel in the right bank of

reverse polarity protector, you should

cylinders and the number 4 is the other cylinder in

take special precautions when con-

this bank.

necting and disconnecting electrical

e. Starting Motor. The starting motor has a

leads and cables. Do not reverse battery

Bendix drive gear which engages the flywheel ring

connections. Do not operate engine with

gear when the starter switch pushbutton is

battery disconnected from the system.

depressed. The starting motor disengages when the

Make sure you connect any booster

button is released. You maintain die starting motor

batteries properly. When you use a fast

by replacing the brushes when worn.

battery charger, disconnect at lease one

f. Oil Pressure Safety Switch. The oil pressure

battery lead. Failure to follow these

4-15