Yamaha YFZ450S 2003 Service Manual page 351

EBS01066
3. Charging voltage
• Connect the engine tachometer to on to
the ignition coil.
• Connect the pocket tester (DC 20 V) to the
battery as shown.
Positive tester probe →
positive battery terminal 1
Negative tester probe →
negative battery terminal 2
• Start the engine and let it run at approxi-
mately 5,000 r/min.
• Measure the charging voltage.
Charging voltage
14 V at 5,000 r/min
NOTE:
_
Make sure the battery is fully charged.
• Is the charging voltage within specifica-
tion?
NO
YES
The charging circuit
is OK.
CHARGING SYSTEM
EBS01100
4. Charging coil resistance
• Disconnect the A.C. magneto coupler from
the wire harness.
• Connect the pocket tester (Ω × 1) to the
charging coils.
Positive tester probe → white 1
Negative tester probe → ground 2
1
W
• Measure the charging coil resistance.
Charging coil resistance
0.288 ~ 0.432 Ω at 20 °C (68 °F)
5. Wiring
• Check the entire charging system's wiring.
Refer to "CIRCUIT DIAGRAM".
• Is the charging system's wiring properly
connected and without defects?
Replace the rectifier/
regulator.
8 - 28
ELEC
2
Y
YES
Replace the pickup
coil/stator assembly.
YES
Replace the diode
and properly
nect or repair the
charging
wiring.
– +
1
NO
NO
con-
system's