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:

    Removing and installing the cowlings and panel
    Removing and installing the cowlings and panel Cowling A Cowling B Cowling C Cowling D Panel A The cowlings and panel shown need to be removed to perform some of the maintenance jobs described in this chapter. Refer to this section each time a cowling or panel needs to be ...

    Checking the radiator fan motor
    1. Check: Radiator fan motor Faulty/rough movement → Replace. a. Disconnect the radiator fan motor coupler from the wire harness. b. Connect the battery (DC 12 V) as shown. Positive tester probe → blue "1" Negative tester probe → black "2" c. Measure ...

    Supporting the motorcycle
    Since this model is not equipped with a centerstand, follow these precautions when removing the front and rear wheel or performing other maintenance requiring the motorcycle to stand upright. Check that the motorcycle is in a stable and level position before starting any maintenance. A ...

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