Yamaha YZF-R125 Service Manual: Checking the transmission
1. Measure:
- Main axle runout
(with a centering device and dial gauge "1")
Out of specification
Replace
the main axle.

2. Measure:
- Drive axle runout
(with a centering device and dial gauge "1")
Out of specification
Replace
the drive axle. 

3. Check:
- Transmission gears
Blue discoloration/pitting/wear
Replace
the defective gear(s).
- Transmission gear dogs
Cracks/damage/rounded edges
Replace
the defective gear(s).

4. Check:
- Transmission gear engagement
(each pinion gear to its respective wheel
gear)
Incorrect
Reassemble the
transmission
axle assemblies.
5. Check:
- Transmission gear movement
Rough movement
Replace the
defective
part(s).
1. Check:
Shift drum groove
Damage/scratches/wear Replace
the shift
drum assembly.
Shift drum segment "1"
Damage/wear Replace the
shift drum assembly.
Shift drum bearing "2" ...
1. Check:
Long clutch push rod
Cracks/damage/wear Replace the
long
clutch push rod.
2. Measure:
Push rod bending limit
Out of specification Replace
the long
clutch push rod. ...
Other materials:
Engine specifications
...
Checking the primary driven gear
1. Check:
Primary driven gear "1"
Damage/wear Replace the
primary drive
gear and clutch housing as a set.
Excessive noise during operation
Replace
the primary drive gear and clutch housing as
a set.
...
Adjusting the brake pedal free play
Adjusting the brake pedal free play
Brake pedal free play
The brake pedal free play should measure
3.5-4.5 mm (0.14-0.18 in) as
shown. Periodically check the brake
pedal free play and, if necessary, have
a Yamaha dealer adjust it.
WARNING
An incorrect brake pedal free play
in ...
2026 Copyright www.yam-r125.net |