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:

    Installing the cylinder head
    1. Install: Cylinder head NOTE: Pass the timing chain through the timing chain cavity. 2. Tighten: Cylinder head bolts "1" Cylinder head bolts "2" NOTE: Lubricate the cylinder head bolts and washers with engine oil. Tighten the cylinder head bolts in the proper tighten ...

    Checking the engine oil level
    1. Stand the vehicle on a level surface. NOTE: Place the vehicle on a suitable stand. Make sure the vehicle is upright. 2. Start the engine, warm it up for several minutes, and then turn it off. 3. Check: Engine oil level The engine oil level should be between the minimum level ...

    Removing the rear brake caliper
    NOTE: Before disassembling the brake caliper, drain the brake fluid from the entire brake system. 1. Remove: Union bolt "1" Copper washers "2" Brake hose "3" NOTE: Put the end of the brake hose into a container and pump out the brake fluid carefully. ...

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