Starter motor brushes sticking in brush
A dirty or worn armature commutator.
A shorted, open or grounded armature.
touching each other) will be indicated by slow
speed and high current.
Open armature (broken wire) may not turn or
will have low RPM.
touching armature) will not turn or may turn
DISASSEMBLY OF STARTER MOTOR
Study Fig. 50 prior to Starter Motor Disassembly.
Remove the starter cover, nylon spur gear retainer and
the nylon spur gear. The three screws holding the gear
cover and the gear itself may now be removed. Lift the
clutch assembly and the pinion gear off their respective
Remove the starter motor thru bolts. Separate motor
end head from motor housing. Fig. 56. Push motor
armature out through bottom of starter housing, taking
care to slide rubber mounted terminal out of motor
housing along with end cap. Fig. 57.
Fig. 56 - Removing Thru Bolts
Fig. 57 - Removing Armature
Before removing armature from end cap, check brushes
for freedom of movement. If brushes are found to be
sticking in their retainers, this must be corrected, or poor
starter motor performance will result. Fig. 58. If
brushes are worn to a length of 1/4" (6.4 mm) or less, the
brushes should be replaced. Check brush springs for
proper tension (sufficient force to keep brush in firm
contact with commutator).
Fig. 58 - Checking Brushes
Clean all dirt accumulations from armature, end cap,
motor support, gears, etc. The end cap bearings and
armature should not be soaked in a solvent. The
armature commutator may be cleaned with a fine
sandpaper or commutator paper. Do not use aluminum
oxide paper or emery cloth, as emery will embed in the
commutator and cause rapid brush wear.
If the armature is suspected to be defective, a new
armature should be tried in the motor. If proper testing
equipment is available, check the suspected armature to
determine if it is defective.