YAMAHA YZ250F FUEL CIRCUIT PUMP DIAGRAM AND TROUBLESHOOTING

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2.

AC magneto

3.

Rectifier/regulator

4.

Joint connector

6.

Engine ground

7.

Battery

8.

Frame ground

9.

Fuse

16.

ECU (Engine Control Unit)

20.

Fuel pump

25.

Engine stop switch

A.

Battery sub-lead

B.

Wire harness

TROUBLESHOOTING

The fuel pump fails to operate.

Before troubleshooting, remove the following part(s):

  • Seat

  • Side cover (left/right)

  • Air scoop (left/right)

  • Fuel tank

  • Air filter case cover

  1. Check the fuel pump system wire harness connections.

 NG→

Reconnect.
OK↓

  1. Check the fuse.

    Refer to CHECKING THE FUSES.

 NG→

Replace the fuse(s).
OK↓

  1. Check the battery.

    Refer to CHECKING AND CHARGING THE BATTERY.

 NG→

  • Clean the battery terminals.

  • Recharge or replace the battery.
OK↓

  1. Check the engine stop switch.

    Refer to CHECKING THE SWITCHES.

 NG→

Replace the engine stop switch.
OK↓

  1. Check fuel pressure.

    Refer to CHECKING THE FUEL PRESSURE.

 NG→

Replace the fuel pump.
OK↓

  1. Check the fuel pump system wire harness connections.

    Refer to CIRCUIT DIAGRAM.

 NG→

Repair or replace the wire harness.
OK↓

Replace the ECU.

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