Kubota M5040, Workshop Manual

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9-S43
M5040, M6040, M7040, WSM ELECTRICAL SYSTEM
6. SERVICING
[1] STARTER
Commutator and Mica
1. Check the contact face of the commutator for wear, and grind the
commutator with emery paper if it is slightly worn.
2. Measure the commutator O.D. with an outside micrometer at
several points.
3. If the minimum O.D. is less than the allowable limit, replace the
armature.
4. If the difference of the O.D.’s exceeds the allowable limit, correct
the commutator on a lathe to the factory specification.
5. Measure the mica undercut.
6. If the undercut is less than the allowable limit, correct it with a saw
blade and chamfer the segment edges.
W1017092
Brush Wear
1. If the contact face of the brush is dirty or dusty, clean it with emery
paper.
2. Measure the brush length ( A ) with vernier calipers.
3. If the length is less than the allowable limit, replace the yoke
assembly and brush holder.
W1017544
Commutator O.D.
Factory spec.
32 mm
1.2598 in.
Allowable limit
31.4 mm
1.2362 in.
Mica undercut
Factory spec.
0.50 to 0.80 mm
0.0197 to 0.0315 in.
Allowable limit
0.20 mm
0.0079 in.
(1) Segment
(2) Depth of Mica
(3) Mica (a) Good
(b) Bad
Brush length ( A )
Factory spec.
18.0 mm
0.7086 in.
Allowable limit
11.0 mm
0.4331 in.
KiSC issued 06, 2008 A