Yamaha 2005 BT1100 Supplementary Service Manual page 88

ELECTRIC STARTING SYSTEM
EAS00769
Checking the starter motor
1. Check:
• commutator
¡
Dirt
2. Measure:
• commutator diameter a
Out of specification
motor.
Min. commutator diameter
27 mm
3. Measure:
• mica undercut a
Out of specification
the proper measurement with a hacksaw
blade which has been grounded to fit the
commutator.
Mica undercut
0.7 mm
NOTE:
The mica must be undercut to ensure proper
operation of the commutator.
4. Measure:
• armature assembly resistances (commuta-
tor and insulation)
Out of specification
motor.
M M M M M M M M M M M M M M M M M M M M M M M M M M M M M
a. Measure the armature assembly resistances
with the pocket tester.
Pocket tester
90890-03112
Armature assembly
Armature coil resistance 1
Insulation resistance 2
Above 1 M at 20°C (68 °F)
b. If any resistance is out of specification,
replace the starter motor.
L L L L L L L L L L L L L L L L L L L L L L L L L L L L L
80
ELEC
Clean with 600 grit sandpaper.
¡
Replace the starter
¡
Scrape the mica to
¡
Replace the starter
0.026 0.034 at 20°C (68 °F)