Yamaha YZF-R125 Service Manual: Poor medium-and-high-speed performance
Refer to "STARTING FAILURES" on page 9-1.
Engine
1. Air filter
- Clogged air filter element
Fuel system
1. Fuel pump
- Faulty fuel pump
Faulty gear shifting
Shifting is difficult
Refer to "Clutch drags".
Incorrect engine idling speed
Engine
1. Cylinder and cylinder head
Incorrect valve clearance
Damaged valve train components
2. Air filter
Clogged air filter element
Fuel system
1. Throttle body
Damaged or loo ...
Shift pedal does not move
Shift shaft
Improperly adjusted shift rod
Bent shift shaft
Shift drum and shift forks
Foreign object in a shift drum groove
Seized shift fork
Bent shift fork guide bar
Transmission ...
Other materials:
Removing the fuel tank
1. Extract the fuel in the fuel tank through the
fuel tank filler hole with a pump.
2. Remove:
Fuel hose connector cover "1"
3. Disconnect:
Fuel hose "2"
CAUTION:
Be sure to disconnect the fuel hose by
hand. Do not forcefully disconnect the
hose with tools.
A ...
Installing the front brake master cylinder
1. Install:
Brake master cylinder "1"
Brake master cylinder holder "2"
NOTE:
Install the brake master cylinder holder with the
arrow mark "a" pointing forward.
Align the end of the brake master cylinder holder
with the punch mark "b" on the handlebar.
First, tighten the front bo ...
Removing the generator
1. Remove:
Generator rotor nut "1"
Washer
NOTE:
While holding the generator rotor "2" with the
sheave holder "3", loosen the generator rotor
nut.
Do not allow the sheave holder to touch the
projection on the generator rotor.
2. Remove:
Generator rotor "1"
(with the ...