Yamaha YZ250F User Manual

ELECTRICAL COMPONENTS
8-46
EAS1SM5347
CHECKING THE INTAKE AIR PRESSURE
SENSOR
1. Check:
• Intake air pressure sensor output voltage
Out of specification  Replace.
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a. Connect the pocket tester (20 VDC) to the
intake air pressure sensor coupler (wire har-
ness side).
b. Start the engine.
c. Measure the intake air pressure sensor out-
put voltage.
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EAS1SM5348
CHECKING THE INTAKE AIR TEMPERA-
TURE SENSOR
1. Remove:
• Intake air temperature sensor
(from the air filter case)
EWA1DX1010
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.
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a. Connect the pocket tester ( 1k/100) to
the intake air temperature sensor terminal.
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EAS1SM5349
CHECKING THE NEUTRAL SWITCH
1. Remove:
• Neutral switch
2. Check:
• Neutral switch
Out of specification  Replace.
Intake air pressure sensor output
voltage
3.57–3.71 V at 101.3 kPa
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Pink/Black “1”
• Negative tester probe 
Black/Blue “2”
1
2
P/B
P/B
Intake air temperature sensor re-
sistance
290–390  at 80 °C (176 °F)
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Brown/White “1”
• Negative tester probe 
Black/Blue “2”
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
12

Yamaha YZ250F Specifications

General

Displacement	250cc
Bore x Stroke	77.0 mm x 53.6 mm
Final Drive	Chain
Suspension / Rear	KYB® single shock; fully adjustable, 12.5-in travel
Brakes / Front	Hydraulic single disc brake, 270mm
Brakes / Rear	Hydraulic single disc brake, 240mm
Fuel Capacity	1.6 gal
Engine Type	Liquid-cooled, DOHC, 4-stroke
Fuel Delivery	Fuel injection
Ignition	TCI
Transmission	5-speed; multiplate wet clutch
Suspension / Front	KYB® Speed-Sensitive System inverted fork; fully adjustable, 12.2-in travel
Tires / Front	80/100-21