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).
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:
Troubleshooting
Any of the following fail to light: headlight, high beam indicator light,
taillight, license plate light, auxiliary
light or meter light.
NOTE:
Before troubleshooting, remove the following part(s):
1. Seats
2. Fuel tank
...
Installing the drive chain
1. Lubricate:
Drive chain
Master link
2. Install:
Drive sprocket
Drive sprocket retainer bolts
3. Install:
Master link
O-rings
Master link plate
Master link clip "1"
CAUTION:
The closed end of the master link clip must
face in the direction of drive ch ...
Checking the rear brake caliper
1. Check:
Brake caliper piston "1"
Rust/scratches/wear Replace the
brake
caliper piston.
Brake caliper cylinder "2"
Scratches/wear Replace the
brake caliper
assembly.
Brake caliper body "3"
Cracks/damage Replace the
brake caliper
assembly.
Brake fluid deli ...