Yamaha TT-R125E(R), Owner'S Service Manual, Page: 564 / 578

6 - 13
– +
ELEC
INSPECTION AND REPAIR
1. Inspect:
●
Commutator
Dirt
→
Clean it with #600 grit sandpaper.
2. Measure:
●
Commutator diameter
a
Out of specification
→
Replace the
starter motor.
3. Measure:
●
Mica undercut
a
Out of specification
→
Scrape the mica
to the proper value (a hacksaw blade
can be ground to fit).
NOTE:
The mica insulation of the commutator must be
undercut to ensure proper operation of com-
mutator.
Commutator wear limit:
21.0 mm (0.83 in)
Mica undercut:
1.5 mm (0.06 in)
4. Measure:
●
Armature assembly resistance (com-
mutator and insulation)
Out of specification
→
Replace the
starter motor.
Measurement steps:
●
Measure the armature assembly resis-
tances with the pocket tester.
Pocket tester
YU-3112-C/90890-03112
Armature coil:
Commutator resistance 1
0.017 ~ 0.021
Ω
at 20 ˚C (68 ˚F)
Insulation resistance 2
Above 1 M
Ω
at 20 ˚C (68 ˚F)
●
If any resistance is out of specification,
replace the starter motor.
ELECTRIC STARTING SYSTEM