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:

    Circuit diagram
    4. Main fuse 5. Main switch 9. Battery 14.Neutral switch 25.ECU (engine control unit) 31.Fuel sender 34.Rear brake light switch 35.Front brake light switch 37.Tail/brake light 38.Rear right turn signal light 39.Rear left turn signal light 40.Front right turn signal light 41.Front lef ...

    Disassembling the front fork legs
    The following procedure applies to both of the front fork legs. 1. Remove: Rubber cap Clip "1" Front fork cap "2" (with O-ring) Fork spring NOTE: Push the front fork cap in the direction of the arrow shown in the illustration to remove the clip. 2. Drain: Fork oil NOTE ...

    Protective apparel
    The majority of fatalities from motorcycle accidents are the result of head injuries. The use of a safety helmet is the single most critical factor in the prevention or reduction of head injuries. Always wear an approved helmet. Wear a face shield or goggles. Wind in your unprotecte ...

    2025 Copyright www.yam-r125.net |