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:
Installing the engine
1. Install:
Engine "1"
Engine mounting bolt (rear lower side) "2"
Engine mounting nut (rear lower side) "3"
Engine mounting bolt (rear upper side) "4"
Engine mounting nut (rear upper side) "5"
Engine mounting bolt (front side) "6"
Engine mounting nut (front side) "7"
NOTE:
Do not ...
Checking the fuses
The following procedure applies to all of the fuses.
CAUTION:To avoid a short circuit, always turn the
main
switch to "OFF" when checking or replacing
a fuse.
1. Remove:
Rider seat
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Fuse
a. Connect the pocket te ...
Engine break-in
There is never a more important period
in the life of your engine than the period
between 0 and 1000 km (600 mi). For
this reason, you should read the following
material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1000 km (600 mi). The vari ...