Checking The Fuel Injector - Yamaha YZ450F Owner's Service Manual

Continuity
Positive tester probe 
Sky blue "1"
Negative tester probe 
Sensor terminal "a"
Continuity
Positive tester probe 
Black/Yellow "2"
Negative tester probe 
Sensor terminal "b"
Continuity
Positive tester probe 
Pink "3"
Negative tester probe 
Sensor terminal "b"
c a

CHECKING THE FUEL INJECTOR

EAS1SL5349
1. Remove:
• Fuel injector
Refer to "THROTTLE BODY" on page 7-5.
2. Check:
• Fuel injector resistance
Out of specification  Replace.
Fuel injector resistance
12.0 
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a. Disconnect the fuel injector coupler from the
fuel injector.
b. Connect the pocket tester (  10) to the
fuel injector coupler.
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Injector terminal "1"
• Negative tester probe 
Injector terminal "2"
2
3
B/Y P
Sb
1
b
ELECTRICAL COMPONENTS
c. Measure the fuel injector resistance.
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