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:
Checking the ignition timing
NOTE:
Prior to checking the ignition timing, check the
wiring connections of the entire ignition system.
Make sure all connections are tight and free of
corrosion.
1. Remove:
Rider seat
Left lower side cowling
Refer to "GENERAL CHASSIS" on page 4-1.
2. Remove:
Timing mark acces ...
Adjusting the throttle cable free play
NOTE:
Prior to adjusting the throttle cable free play, the
engine idling speed should be adjusted.
1. Check:
Throttle cable free play "a"
Out of specification →Adjust.
2. Remove:
Right side panel
Refer to "GENERAL CHASSIS" on page 4-1.
3. Adjust:
Throttle cable f ...
Circuit diagram
4. Main fuse
5. Main switch
9. Battery
25.ECU (engine control unit)
36.License plate light
37.Tail/brake light
44.Headlight relay
46.Pass switch
47.Dimmer switch
51.Headlight (low beam)
52.Auxiliary light
54.Headlight (high beam)
58.Meter light
60.High beam indicator light
64.Ignit ...