Yamaha YZF-R125 Service Manual: Checking the fuel sender

1. Drain the fuel from the fuel tank.

2. Check:

Fuel sender resistance Out of specification → Replace the fuel sender.


a. Connect the pocket tester ( ×
10) to the fuel sender coupler as shown.


  • Positive tester probe
    sky blue "1"
  • Negative tester probe
    orange/white "2"

Checking the fuel sender


A. Full fuel tank position

B. Empty fuel tank position

b. Measure the fuel sender resistance.

    Checking the horn
    1. Check: Horn resistance Out of specification Replace. a. Disconnect the horn connectors from the horn terminals. b. Connect the pocket tester ( × 1) to the horn terminals. Positiv ...

    Checking the speed sensor
    1. Check: Speed sensor output voltage Out of specification → Replace. a. Connect the pocket tester (DC 20 V) to the speed sensor coupler (wire harness end) as shown. Positive tester pro ...

    Other materials:

    Troubleshooting charts
    Starting problems or poor engine performance Starting problems or poor engine performance Engine overheating WARNING Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be blown out under pressure, which could cause serious injury. Be ...

    Starting failures
    Engine 1. Cylinder and cylinder head - Loose spark plug - Loose cylinder head or cylinder - Damaged cylinder head gasket - Damaged cylinder gasket - Worn or damaged cylinder - Incorrect valve clearance - Improperly sealed valve - Incorrect valve-to-valve-seat contact - Incorrect valve timi ...

    Checking the fid (fast idle solenoid)
    1. Disconnect: FID (fast idle solenoid) coupler 2. Check: FID (fast idle solenoid) resistance a. Disconnect the FID (fast idle solenoid) coupler from the FID. b. Connect the pocket tester ( × 10) to the terminals of the FID (fast idle solenoid). Positive tester probe ...

    2026 Copyright www.yam-r125.net |