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:

Drive chain slack
The drive chain slack should be checked before each ride and adjusted if necessary. To check the drive chain slack Place the motorcycle on the sidestand. TIP When checking and adjusting the drive chain slack, there should be no weight on the motorcycle. Shift the transmission in ...

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, ...

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 ...