Checking The Starter Motor - Yamaha 2004 YP400 Service Manual

STARTER MOTOR
EAS00770

CHECKING THE STARTER MOTOR

1. Check:
• commutator
Dirt → Clean with 600 grit sandpaper.
2. Measure:
• commutator diameter a
Out of specification → Replace the starter
motor.
Commutator wear limit
27 mm (1.06 in)
3. Measure:
• mica undercut a
Out of specification → Scrape the mica to
the proper measurement with a hacksaw
blade that has been grounded to fit the
commutator.
Mica undercut
0.7 mm (0.028 in)
NOTE:
_
The mica of the commutator must be undercut
to ensure proper operation of the commutator.
4. Measure:
• armature assembly resistances (commuta-
tor and insulation)
Out of specification → Replace the starter
motor.
M MMM M MMM M M MMM
a. Measure the armature assembly resis-
tances with the pocket tester.
Pocket tester
90890-03112, YU-03112-C
Armature coil
Commutator resistance 1
0.0012 ~ 0.0022 Ω at 20 °C
(68 °F)
Insulation resistance 2
Above 1 MΩ at 20 °C (68 °F)
b. If any resistance is out of specification,
replace the starter motor.
L LLL L LLL L L LLL
8 - 21
ELEC
M M MMM M M MMM M
L L LLL L L LLL L
– +
M MMM M MMM
L LLL L LLL