TM 5-4240-501-14&P
Fig. 53 - Starter Key Switch
CHECKING THE STARTER MOTOR
DRIVE AND CLUTCH
When the starter switch is activated, the nylon spur gear
should rise, engaging the flywheel ring gear, and crank
the engine. This action can be observed by removing
the starter cover. If the starter motor drive does not
react properly, inspect the helix and the nylon spur gear
for freeness of operation. If any sticking occurs, this
must be corrected. Proper operation of the starter is
dependent on the nylon spur gear freely moving on the
helix. See Fig. 54.
NOTE: Do not oil nylon spur gear or clutch helix.
Fig. 54 - Starter Motor Drive
The starter motor clutch is designed to prevent damage
from shock loads such as an engine backfire. The clutch
should not slip during normal engine cranking. This can
be checked by blocking the mower blade and engaging
the starter motor. If the clutch assembly slips at this
time, it should be replaced.
STARTERS
Nicad System
CAUTION: Remove spark plug high tension wire prior to
this test if starter motor is mounted on engine.
CHECKING THE STARTER MOTOR
A performance test of the starter motor may be made in
the following manner.
Equipment Needed -
A tachometer capable of reading 1500 RPM.
An ammeter capable of reading 0 to 5 amps.
A fully charged battery.
Connect the starter motor, battery and ammeter, as
shown in the illustration. See Fig. 55.
Insert the tachometer in the end of the starter clutch helix
and activate the starter motor.
Fig. 55 - Performance Test
A starter motor in good condition will be within the
following specifications. Starter Motor RPM - 1000
minimum Current - 31/2 Amperes maximum If the starter
motor does not perform satisfactorily, the following
should be checked, and corrected if necessary.
1.
A binding condition between the pinion and clutch
gear or misalignment of motor bearings.
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