Checking The Fuel Pump And Pressure Regulator Operation; Checking The Throttle Position Sensor - Yamaha YP400T, YP400V, YP400W Service Manual

THROTTLE BODY AND FUEL INJECTOR
1
2
4
EAS00915
CHECKING THE FUEL PUMP AND
PRESSURE REGULATOR OPERATION
1. Check:
• pressure regulator operation
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a. Remove the storage box.
Refer to "COWLING AND COVERS" in
chapter 3.
b. Remove the fuel hose connector cover 1
and disconnect the fuel hose 2 from the
fuel pump.
CAUTION:
Although the fuel has been removed from
the fuel tank, be careful when removing the
fuel hose, since there may be fuel remain-
ing in it.
NOTE:
Before removing the hose, place a few rags in
the area under where it will be removed.
3
c. Connect the pressure gauge 3 and adapter
4 onto the fuel hose.
Pressure gauge
Adapter
d. Start the engine.
e. Measure the fuel pressure.
Fuel pressure
Faulty → Replace the fuel pump.
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EAS00916
CHECKING THE THROTTLE POSITION
SENSOR
1. Check:
• throttle position sensor
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a. Connect the pocket tester (DC 20 V) to the
terminals of the throttle position sensor.
7 - 34
FI
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90890-03153, YU-03153
90890-03181, YM-03181
246 ~ 254 kPa
2
(2.46 ~ 2.54 kg/cm ,
35.0 ~ 36.1 psi)
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