Checking The Starter Motor - Yamaha XT660Z 2008 Service Manual

EAS24790

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.
Limit
27.0 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 com-
mutator.
Mica undercut (depth)
0.70 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.
ELECTRIC STARTER
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Measure the armature assembly resistances
with the pocket tester.
Pocket tester
90890-03112
Armature coil
Commutator resistance "1"
0.025–0.035 Ω at 20°C (68°F)
Insulation resistance "2"
Above 1 M at 20°C (68°F)
b. If any resistance is out of specification, re-
place the starter motor.
5. Measure:
• Brush length "a"
Out of specification → Replace the brushes
as a set.
Limit
5.00 mm (0.20 in)
6. Measure:
• Brush spring force
Out of specification → Replace the brush
springs as a set.
Brush spring force
7.65-10.01 N (27.51-36.01 oz)
(780-1,021 gf)
5-58