Checking The Intake Air Temperature Sensor; Checking The Fuel Injector - Yamaha YZ 2018 Series Owner's Service Manual

• Positive tester probe 
Pink "1"
• Negative tester probe 
Black/Blue "2"
2
b. Start the engine.
c. Measure the intake air pressure sensor out-
put voltage.
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EASB29B367
CHECKING THE INTAKE AIR TEMPERA-
TURE SENSOR
1. Remove:
• Intake air temperature sensor
(from the air filter case)
EWA
WARNING
• Handle the intake air temperature sensor
with special care.
• Never subject the intake air temperature
sensor to strong shocks. If the intake air
temperature sensor is dropped, replace it.
2. Check:
• Intake air temperature sensor resistance
Out of specification  Replace.
Intake air temperature sensor re-
sistance
5400.0–6600.0  at 0 °C (5400.0–
6600.0  at 32 °F)
Intake air temperature sensor re-
sistance
290–389  at 80 °C (290–389  at
176 °F)
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a. Connect the digital circuit tester () to the in-
take air temperature sensor terminal.
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with
tachometer
YU-A1927
1
8-72
ELECTRICAL COMPONENTS
• Positive tester probe 
Brown/White "1"
• Negative tester probe 
Black/Blue "2"
1 2
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EASB29B368

CHECKING THE FUEL INJECTOR

1. Remove:
• Fuel injector
Refer to "THROTTLE BODY" on page 7-6.
2. Check:
• Fuel injector resistance
Out of specification  Replace.
Resistance
12.0 
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a. Disconnect the fuel injector coupler from the
fuel injector.
b. Connect the digital circuit tester () to the
fuel injector coupler.
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with
tachometer
YU-A1927
• Positive tester probe 
Injector terminal "1"
• Negative tester probe 
Injector terminal "2"
1 2