Yamaha TDM850 1996 Service Manual page 293

ELECTRIC STARTING SYSTEM
Inspection and repair
1. Inspect:
2. Measure:
3. Measure:
NOTE:
The mica insulation of the commutator must be
undercut to ensure proper operation of commuta-
tor.
4. Inspect:
Inspecting steps:
8-17
S Commutator
Dirty ! Clean it with #600 grit sandpaper.
S Commutator diameter a
Out of specification ! Replace starter motor.
Commutator wear limit:
27 mm
S Mica undercut b
Out of specification ! Scrape the mica to prop-
er value using a hacksaw blade can be ground
to fit.
Mica undercut:
0.7 mm
S Armature coil (insulation/continuity)
Defects ! Replace starter motor.
S Connect the pocket tester for continuity check
1 and insulation check 2 .
S Measure the armature resistances.
Armature coil resistance:
Continuity check 1 :
0.01 Ω at 20_C
Insulation check 2 :
More than 1 MΩ at 20_C
S If the resistance is incorrect, replace the starter
motor.
ELEC