Yamaha CS50 User Manual

ELEC
ELECTRIC STARTING SYSTEM
8-17
REMOVING THE STARTER MOTOR
1. Remove:
• exhaust pipe assembly
• rear wheel
• starter motor
EAS00769
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:
• armature assembly resistances (commuta-
tor and insulation)
Out of specification
 Replace the starter
motor.

a. Measure the armature assembly resistances
with the pocket tester.
b. If any resistance is out of specification,
replace the starter motor.

4. Measure:
• brush length a
Out of specification
 Replace the brushes
as a set.
Commutator wear limit
14.8 mm
Pocket tester
90890-03112
Armature coil
Commutator resistance

0.064 ~ 0.079 Ω at 20°C
Insulation resistance 
Above 1 MΩ at 20°C
Brush length wear limit
0.9 mm


a
a

Yamaha CS50 Specifications

General

Fuel Capacity	4.5 liters
Fuel System	Carburetor
Cooling	Air-cooled
Transmission	Automatic
Starting System	Kick start
Brakes	Drum brakes (front and rear)