Checking The Rectifier/Regulator; Checking The Speed Sensor; Checking The Fuel Sender - Yamaha WR450FB 2012 Owner's Service Manual

b. Measure the stator coil resistance.
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EAS1DX3237

CHECKING THE RECTIFIER/REGULATOR

1. Check:
• Charging voltage
Out of specification
regulator.
Charging voltage
14 V at 5000 r/min
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a. Set the digital tachometer to the ignition coil.
b. Connect the pocket tester (DC 20 V) to the
rectifier/regulator coupler as shown.
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe
Red "1"
• Negative tester probe
Black "2"
c. Start the engine and let it run at approxi-
mately 5000 r/min.
d. Measure the charging voltage.
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1 2 3
Replace the rectifier/
1 2
ELECTRICAL COMPONENTS
EAS28240

CHECKING THE SPEED SENSOR

1. Check:
• Speed sensor output voltage
Out of specification
Output voltage reading cycle
0.6V to 4.8V to 0.6V to 4.8V
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a. Connect the test harness-speed sensor (3P)
to the speed sensor coupler and wire har-
ness as shown.
b. Connect the pocket tester (DC20V) to the
test harness-speed sensor (3P).
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
Test harness-speed sensor 5TJ
(3P)
90890-03228
YU-03228
• Positive tester probe
White "1"
• Negative tester probe
Black/white "2"
2
B/W R
c. Set the main switch to "ON".
d. Elevate the front wheel and slowly turn it.
e. Measure the voltage (DC 5 V) of white and
black/white. With the front wheel slowly ro-
tating, voltage alternates between 0 V and 5
V.
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EAS1DX3238

CHECKING THE FUEL SENDER

Drain the gasoline.
1. Disconnect:
• Fuel sender coupler
(from the fuel sender)
9-74
Replace.
1
W