Yamaha YZF-R125 Service Manual: Troubleshooting

Circuit diagram

4. Main fuse 5. Main switch 9. Battery 17.Engine stop switch 25.ECU (engine control unit) 30.Fuel pump 64.Ignition fuse ...

Electrical components

1. Main switch 2. Clutch switch 3. Front brake light switch 4. Ignition coil 5. Throttle body sensor assembly (intake air pressure sensor, intake air temperature sensor, throttle position se ...

Other materials:

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 " ...

Parking
When parking, stop the engine, and then remove the key from the main switch. WARNING Since the engine and exhaust system can become very hot, park in a place where pedestrians or children are not likely to touch them and be burned. Do not park on a slope or on soft ground, ...

Checking the camshaft
1. Check: Camshaft lobes Blue discoloration/pitting/scratches  Replace the camshaft. 2. Measure: Camshaft lobe dimensions "a" and "b" Out of specification Replace the camshaft. 3. Check: Camshaft oil passage Obstruction Blow out with compressed air. ...