Yamaha XMAX 125, Service Manual

Page: 291 / 498

ELECTRIC STARTER (YP125R)
5-46
EAS37P1045
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.
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.
TIP
The mica of the commutator must be undercut to
ensure proper operation of the commutator.
4. Measure:
• Armature assembly resistances (commutator
and insulation)
Out of specification
→
Replace the starter
motor.
▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼▼▼
a. Measure the armature assembly resistances
with the digital circuit tester.
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.
6. Measure:
• Brush spring force
Out of specification
→
Replace the brush
springs as a set.
Limit
16.6 mm (0.65 in)
Mica undercut (depth)
1.35 mm (0.05 in)
Digital circuit tester
90890-03174
Model 88 Multimeter with ta-
chometer
YU-A1927
Armature coil
Commutator resistance “1”
Continuity (0.0378–0.0462
Ω
at
20 °C (68 °F))
Insulation resistance “2”
No continuity (Above 1 M
Ω
at 20
°C (68 °F))
Limit
3.50 mm (0.14 in)
Brush spring force
3.92–5.88 N (400–600 gf, 14.11–
21.17 oz)