Checking The Crankshaft Position Sensor; Checking The Ecu; Checking The Stator Coil - Yamaha YZ450FF 1SL-28199-11 Owner's Service Manual

b. Measure the primary coil resistance.
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3. Check:
• Secondary coil resistance
Out of specification  Replace.
Secondary coil resistance
8.64–12.96 k
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a. Connect the pocket tester (  1k) to the ig-
nition coil.
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Ignition coil terminal 1 "1"
• Negative tester probe 
Spark plug lead "2"
b. Measure the secondary coil resistance.
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CHECKING THE CRANKSHAFT POSITION
EAS1SL5340
SENSOR
1. Disconnect:
• Crankshaft position sensor coupler
(from the wire harness)
ELECTRICAL COMPONENTS
2. Check:
• Crankshaft position sensor resistance
Out of specification  Replace.
Crankshaft position sensor resis-
tance
228–342 
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a. Connect the pocket tester (  100) to the
crankshaft position sensor coupler.
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Gray "1"
• Negative tester probe 
Black "2"
b. Measure the crankshaft position sensor re-
sistance.
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EAS1SL5341

CHECKING THE ECU

1. Check:
• Mounted condition of ECU.
Improperly mounted  Remount.
TIP
• The lean angle sensor is built into the ECU.
• The lean angle sensor stops the engine in
case of a turnover.
• To ensure that the lean angle sensor operates
correctly, do not change the installed condi-
tion of the ECU.

CHECKING THE STATOR COIL

EAS1SL5342
1. Disconnect:
• Stator coil coupler
(from the wire harness)
8-42
1 2
Gy B