Yamaha WR450F(T) Owner's Service Manual page 708

W
Y
1 R
2
B
LIGHTING SYSTEM
AC MAGNETO INSPECTION
1. Inspect:
• Lighting coil resistance
Out of specification → Replace.
Tester (+) lead → Yellow lead 1
Tester (–) lead → Ground 2
Lighting coil
resistance
0.224 ~ 0.336 Ω
at 20 °C (68 °F)
RECTIFIER/REGULATOR INSPECTION
1. Connect the battery leads.
2. Start the engine.
3. Turn on the headlight and taillight by turn-
ing on the lights switch.
4. Inspect:
• Out-put voltage
Out of specification → Replace rectifier/
regulator.
Tester (+) lead → Yellow lead 1
Tester (–) lead → Black lead 2
Out-put voltage
13.0 ~ 14.0 V at
5,000 r/min
6 - 25
– +
ELEC
Tester selector
position
Ω × 1
Tester selector
position
ACV-20