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 camshaft sprocket and timing chain guide
1. Check:
Camshaft sprocket
More than 1/4 tooth wear "a" Replace
the
camshaft sprocket, timing chain and crankshaft
as a set.
a. 1/4 tooth
b. Correct
1. Timing chain roller
2. Camshaft sprocket
2. Check:
Timing chain guide (exhaust side)
Damage/wear Replace.
...
Checking the front brake master cylinder
1. Check:
Brake master cylinder
Damage/scratches/wear Replace.
Brake fluid delivery passages
(brake master cylinder body)
Obstruction Blow out with
compressed air.
2. Check:
Brake master cylinder reservoir
Cracks/damage Replace the brake
master
cylinder.
Brake maste ...
Removing the rear wheel (disc)
1. Stand the vehicle on a level surface.
WARNINGSecurely support the vehicle
so that there is
no danger of it falling over.
2. Elevate:
Rear wheel
NOTE:
Place the vehicle on a suitable stand so that the
rear wheel is elevated.
3. Remove:
Rear brake caliper
NOTE: ...