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:
Throttle position sensor
1. Check:
Throttle position sensor
a. Connect the digital circuit tester to the terminals
of the throttle body sensor assembly
coupler as shown.
Positive tester probe →
gray/red terminal "1"
Negative tester probe →
gray/black terminal "2"
b. Measure the throttle pos ...
Multi-function display
1. Multi-function display
2. "RESET/SELECT" button
The multi-function display is equipped with the
following:
a speedometer (which shows the riding speed)
an odometer (which shows the total distance
traveled)
two tripmeters (which show the distance traveled
since they were last ...
Checking the water pump
1. Check:
Water pump housing cover
Water pump housing
Cracks/damage Replace.
Impeller shaft
Cracks/damage/wear Replace.
Bearing
Rough movement Replace.
Radiator outlet hose
Cracks/damage Replace.
...