Checking The Starter Motor - Yamaha 2011 FZ8NA(C) Service Manual

EAS24791

CHECKING THE STARTER MOTOR

1. Check:
• Commutator
Dirt → Clean with 600 grit sandpaper.
2. 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 (depth)
0.70 mm (0.03 in)
TIP
The mica of the commutator must be undercut
to ensure proper operation of the commutator.
3. Measure:
• Armature assembly resistances (commu-
tator and insulation)
Out of specification → Replace the
starter motor.
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a. Measure the armature assembly resis-
tances with the digital circuit tester.
Digital circuit tester
90890-03174
Model 88 Multimeter with
tachometer
YU-A1927
Armature coil
Commutator resistance
0.0100–0.2000 Ω at 20 °C (68
°F)
Insulation resistance
Above 1 MΩ at 20 °C (68 °F)
ELECTRIC STARTER
b. If any resistance is out of specification,
replace the starter motor.
1. Commutator resistance
2. Insulation resistance
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
4. Measure:
• Brush length "a"
Out of specification → Replace the brush
holder set.
Brush overall length
12.0 mm (0.47 in)
Limit
6.50 mm (0.26 in)
5. Measure:
• Brush spring force
Out of specification → Replace the brush
holder set.
Brush spring force
6.02–6.51
21.65–23.41 ozf)
5-43
N (614–664 gf,