Yamaha YB50 Service Manual page 141

TROUBLESHOOTING
NOTE:
• Remove the following parts before carrying out the repair of the fault.
1) Side covers (right and left)
2) Rear cover
• Use the following special tool for this repair.
Inductive tachometer:
90890-03113
1. Fuse (main)
• Remove the fuse.
• Connect the pocket tester (Ωx1) to the
fuse.
• Check the fuse to see if there is continuity
2. Battery
• Check the condition of the battery.
See chapter 3, section "INSPECTION OF
THE BATTERY".
Open circuit voltage:
12.8 V or more at 20 °C (68 °F)
3. Charging voltage
• Connect the inductive tachometer on the
spark plug cable
• Connect the pocket tester (20 V CC) on the
battery.
Cable (+) of the tester
Cable (–) of the tester
• Start the engine and accelerate to 5,000
rpm/min.
• Check charging voltage.
Charging voltage:
14 ~ 15 V at 5,000 rpm/min.
NOTE:
Use a fully charged battery.
THE BATTERY IS NOT CHARGED
CONTINUITY
CORRECT
Terminal (+)
Terminal (–)
OUTSIDE SPECI-
FIED VALUE
CHARGING SYSTEM
Pocket tester:
90890-03112
NO CONTINUITY
The fuse is defective, change.
INCORRECT
• Clean the battery terminals
• Recharge or change the battery.
SATISFIES THE SPECIFIED VALUE
The charging circuit is in good condition.
7-11
ELEC