Yamaha YZF-R125 Owners Manual: Troubleshooting

Although Yamaha motorcycles receive a thorough inspection before shipment from the factory, trouble may occur during operation. Any problem in the fuel, compression, or ignition systems, for example, can cause poor starting and loss of power.

The following troubleshooting charts represent quick and easy procedures for checking these vital systems yourself. However, should your motorcycle require any repair, take it to a Yamaha dealer, whose skilled technicians have the necessary tools, experience, and know-how to service the motorcycle properly.

Use only genuine Yamaha replacement parts. Imitation parts may look like Yamaha parts, but they are often inferior, have a shorter service life and can lead to expensive repair bills.

WARNING
When checking the fuel system, do not smoke, and make sure there are no open flames or sparks in the area, including pilot lights from water heaters or furnaces. Gasoline or gasoline vapors can ignite or explode, causing severe injury or property damage.

    Rear wheel
    To remove the rear wheel WARNING To avoid injury, securely support the vehicle so there is no danger of it falling over. Loosen the axle nut. Axle nut Drive chain slack adjust ...

    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. S ...

    Other materials:

    Adjusting the rear disc brake
    1. Check: Brake pedal position (distance "a" from the center of the rider footrest to the center of the brake pedal) Out of specification Adjust. 2. Adjust: Brake pedal position a. Loosen the locknut "1". b. Remove the cotter pin "2", washer "3", and pin "4". c. Turn t ...

    Troubleshooting method
    The engine operation is not normal and the engine trouble warning light comes on. 1. Check: Fault code number a. Check the fault code number displayed on the FI diagnostic tool. b. Identify the faulty system with the fault code. Refer to "Self-Diagnostic Function table". c. Identi ...

    Removing the lower bracket
    1. Stand the vehicle on a level surface. WARNINGSecurely support the vehicle so that there is no danger of it falling over. 2. Remove: Upper ring nut Rubber washer Lower ring nut "1" Lower bracket NOTE: Remove the lower ring nut with the steering nut wrench "2". ...

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