Yamaha YZ450F 2021 - Checking the Ignition Coil; Checking the Crankshaft Position Sensor

ELECTRICAL COMPONENTS
8-49
b. Measure the spark plug cap resistance.
EAM30296
CHECKING THE IGNITION COIL
1. Disconnect:
• Ignition coil terminal
(from the sub wire harness)
• Spark plug cap
(from the ignition coil)
2. Check:
• Primary coil resistance
Out of specification  Replace.
a. Connect the digital circuit tester () to the
ignition coil.
b. Measure the primary coil resistance.
3. Check:
• Secondary coil resistance
Out of specification  Replace.
a. Connect the digital circuit tester () to the
ignition coil.
b. Measure the secondary coil resistance.
EAM30297
CHECKING THE CRANKSHAFT POSITION
SENSOR
1. Disconnect:
• Crankshaft position sensor coupler
(from the wire harness)
2. Check:
• Crankshaft position sensor resistance
Out of specification  Replace.
a. Connect the digital circuit tester () to the
crankshaft position sensor coupler.
Primary coil resistance
2.16–2.64 
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with tachom-
eter
YU-A1927
• Positive tester probe 
Ignition coil terminal 1 “1”
• Negative tester probe 
Ignition coil terminal 2 “2”
Secondary coil resistance
8.64–12.96 k
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with tachom-
eter
YU-A1927
• Positive tester probe 
Ignition coil terminal 1 “1”
• Negative tester probe 
Spark plug lead “2”
Crankshaft position sensor resis-
tance
228–342 
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with tachom-
eter
YU-A1927
• Positive tester probe 
Gray “1”
• Negative tester probe 
Black “2”
1