TM 5-4930-207-34
(3) Check field coils for open circuits and
(3) Secure armature in a lathe. With arma-
shorts to ground, or between coils using a test
ture spinning, hold an emery cloth against the
light.
commutator until the copper is bright and smooth.
c. Inspection
f. Reassembly and installation.
(1) Examine field frame assembly for cracks
(1) Reassembly is the reverse of disassem-
or warping, Inspect armature shaft end for dam-
bly. Refer to figure 8-2.
age or wear.
(2) Install the starter assembly as instructed
(2) Examine clutch for broken or cracked
in TM 5-4930-207-12.
teeth.
(3) Examine field coils for worn, burned, and
g. No-Load Test.
frayed insulation. Be certain connections between
(1) Connect the starting motor in series with
field coils are secure. Repair connections if neces-
a fully charged battery, an ammeter capable of
sary.
reading several hundred amperes, and a variable
(4) Inspect springs for distortion or fatigue.
resistor. Also connect a voltmeter from the motor
Examine brushes for damage or excessive wear.
frames. An rpm indicator is necessary to measure
d. Repair.
armature speed.
(1) Replace armature or coils if tests indi-
(2) Obtain the specified voltage of 23 volts
cate shorts.
by varying the resistance unit. The current draw
(2) If commutator is out-of-round in excess
must be 90 amperes maximum and the current
of 0.001 inch, turn down on lathe.
speed at these readings must be a maximum of
( 3 ) Replace damaged or worn solenoid
10,700 rpm.
switch.
(4) Replace all parts indicating wear, cracks,
or damage.
3-5. Engine, Gasoline, Model
(5) Undercut mica insulation between the
4A032-11
commutator bars to a depth of 1/32 of an inch,
a. General. The engine is a four-cylinder, air
When undercutting mica, the cut should be square
cooled, overhead valve, gasoline type which oper-
and free of burrs.
ates the compressor on the lubricating unit.
e. Testing.
b. Removal and Installation. Refer to TM
(1) Check brush holder for shorts to ground
5 - 4 9 3 0 - 2 0 7 - 1 2 for removal and installation
using a test light.
instructions.
(2) Test armature assembly for open coils
c. Repair. Refer to TM 5-2805-208-14 for
and shorts to ground, or between coils by using
engine repair instructions.
a test light.
3-4
