CHARGING & STARTING SYSTEM
Page 2B-18 90-857046R1 NOVEMBER 2001
Cleaning and Inspection
1. Clean all motor parts.
2. Check pinion teeth for chips, cracks or excessive wear.
3. Replace the drive clutch spring and/or collar, if tension is not adequate, or if wear is ex-
cessive.
4. Check that the brush holder is not damaged or is not holding the brushes against the
commutator.
5. Replace brushes that are pitted or worn to less than 1/4 in. (6.4mm) in length. Refer to
“BRUSH REPLACEMENT”, following.
6. Replace a damaged or excessively worn bushing in the end cap.
7. Check the armature conductor (commutator bar junction) for a firm connection. A poor
connection usually results in a burned commutator bar.
8. Re-surface and undercut a rough commutator, as follows:
CAUTION
Do not turn down the commutator excessively.
a. Re-surface the commutator and undercut the insulation between the commutator
bars 1/3 in. (0.8mm) to the full width of the insulation, make sure that the undercut
is flat.
b. Clean the commutator slots after undercutting.
c. De-burr the commutator lightly with No. 00 sandpaper, then clean the commutator.
d. Check the armature on a growler for shorts. See “TESTING”, following.
9. Open-circuited armatures often can be saved where an open circuit is obvious and repairable.
The most likely place for an open circuit is at the commutator bars. Long cranking peri-
ods overheat the starter motor so that solder in the connections melts. The poor connec-
tions cause arcing and burning of the commutator bars.
10. Repair bars, that are not too badly burned, by re-soldering the leads in bars (using rosin
flux solder) and turning down the commutator in a lathe to remove burned material, then
undercut the mica.
11. Clean out the copper or brush dust from slots between the commutator bars.
12. Check the armature for shorts and ground. See “TESTING”.
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