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Starting System
Armature Inspection and Test
1.
Inspect the armature for wear or damage due to
contact with the field coil magnets.
Inspect for
damage.
2.
A dirty or burnt commutator surface may be resur-
faced with emery cloth or a lathe within the follow-
ing specifications.
Commutator Diameter
Standard (New): 29.9-30.0 mm
(1.177-1.181 in)
Service Limit:
VERNIER CALIPER
Table of Contents
29.0 mm (1.142 in)
COMMUTATOR
Commutator Runout
Standard (New): 0—0.02 mm (0-0.0008 in)
Service Limit:
0.05 mm (0.002 in)
3.
If the commutator runout and diameter are within
limits, check the commutator for damage or for car-
bon dust or brass chips between the segments.
4. If the surface is dirty, recondition it with a #500 or
#600 sandpaper. Then, check mica depth. If
necessary, undercut mica with a hacksaw blade to
achieve proper depth.
SANDPAPER
Commutator Mica Depth
Standard (New): 0.5-0.8 mm (0.02-0.03 in)
Service Limit:
0.2 mm (0.008 in)
DIAL
INDICATOR
COMMUTATOR
COMMUTATOR
MICA DEPTH