Yamaha YZF-R125 Service Manual: Checking the transmission

Yamaha YZF-R125 Service Manual / Engine / Transmission / Checking the transmission

1. Measure:

Main axle runout (with a centering device and dial gauge "1") Out of specification Replace
the main axle.

Checking the transmission

2. Measure:

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

Checking the transmission

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).

Checking the transmission

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).

Checking the shift drum assembly

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" ...

Checking the clutch push rods

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:

Checking the rear 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 kit Damage/scratches/wear Replace. 3. Check: Brake fluid reservoir Cracks/ ...

Cleaning and lubricating the drive chain
The drive chain must be cleaned and lubricated at the intervals specified in the periodic maintenance and lubrication chart, otherwise it will quickly wear out, especially when riding in dusty or wet areas. Service the drive chain as follows. NOTICE The drive chain must be lubricated ...

Checking the rocker arms and rocker arm shafts
The following procedure applies to all of the rocker arms and rocker arm shafts. 1. Check: Rocker arm Damage/wear Replace. 2. Check: Rocker arm shaft Blue discoloration/excessive wear/pitting/ scratches Replace or check the lubrication system. 3. Measure: Rocke ...