Yamaha SXV70SJ Supplementary Service Manual page 331

ELECTRICAL STARTING SYSTEM (VX700DX/VT700)
Inspection
1. Inspect:
•
Commutator (outer surface)
Dirty → Clean with #600 grit sandpaper 1.
Hold the armature in a vise 2 and copper or
aluminium plate 3.
CAUTION:
Lightly grip the armature with a vise.
SCH8080
2. Measure:
•
Commutator (diameter)
Measure the diameter a of the commutator at
points where the brush comes in contact.
Out of specification → Replace the starter
motor.
Commutator wear limit a:
SCH8090
3. Measure:
•
Mica (insulation depth) 1
(between commutator segments)
Out of specification → Scrape mica to proper
limits.
Use a hacksaw blade 2 that is ground to fit.
Mica undercut a:
SCH8100
4. Measure:
•
Armature coil resistance
(insulation/continuity)
Defect(s) → Replace the starter motor.
Inspecting steps:
•
Connect the pocket tester for the continuity
check 1 and the insulation check 2.
•
Measure the armature coil resistances.
SCH8110
Armature coil resistance:
•
If the resistance is incorrect, replace the starter
motor.
8-15
ELEC
27 mm (1.06 in)
0.6 mm (0.024 in)
Continuity check 1:
Ω
0.014 ~ 0.018 at 20˚C (68˚F)
Insulation check 2:
Ω
More than 100 k at 20˚ C (68˚F)
– +