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:

    Changing the engine oil
    1. Remove: Right bottom cowling Right upper side cowling Right lower side cowling Refer to "GENERAL CHASSIS" on page 4-1. 2. Start the engine, warm it up for several minutes, and then turn it off. 3. Place a container under the engine oil drain bolt. 4. Install: Engine oil d ...

    Checking the front fork
    1. Stand the vehicle on a level surface. WARNINGSecurely support the vehicle so that there is no danger of it falling over. 2. Check: Inner tube Damage/scratches Replace. Oil seal Oil leakage Replace. 3. Hold the vehicle upright and apply the front brake. 4. Che ...

    Self-diagnostic function table
    If the ECU detects an abnormal signal from a sensor while the vehicle is being driven, the ECU illuminates the engine trouble warning light and provides the engine with alternate operating instructions that are appropriate for the type of malfunction. When an abnormal signal is received fro ...

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