Yamaha 2003 YFZ450S, Service Manual

Page: 351 / 375

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ELEC
CHARGING SYSTEM
EBS01066
NO
YES
EBS01100
YES
NO
YES
NO
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?
The charging circuit
is OK.
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
• Measure the charging coil resistance.
Charging coil resistance
0.288 ~ 0.432
Ω
at 20 °C (68 °F)
Replace the pickup
coil/stator assembly.
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. Replace the diode
and properly con-
nect or repair the
charging system’s
wiring.
W Y
1
2
1