Yamaha YZF-R125 Service Manual: Checking the valve springs

The following procedure applies to all of the valve springs.

1. Measure:

  • Valve spring free length "a" Out of specification Replace the valve spring.

Checking the valve springs


2. Measure:

  • Compressed valve spring force "a" Out of specification Replace the valve spring.

Checking the valve springs


b. Installed length

3. Measure:

  • Valve spring tilt "a" Out of specification Replace the
    valve spring.

Checking the valve springs


    Checking the valve seats
    The following procedure applies to all of the valves and valve seats. 1. Eliminate: Carbon deposits (from the valve face and valve seat) 2. Check: Valve seat Pitting/wear Replace the ...

    Installing the valves
    The following procedure applies to all of the valves and related components. 1. Deburr: Valve stem end (with an oil stone) 2. Lubricate: Valve stem "1" Valve stem seal "2" (with ...

    Other materials:

    Checking the rear brake disc
    1. Remove: Rear wheel Refer to "REAR WHEEL" on page 4-12. 2. Check: Brake disc Damage/galling → Replace. 3. Measure: Brake disc deflection Out of specification → Correct the brake disc deflection or replace the brake disc. Refer to "CHECKING THE FRONT BRAKE DIS ...

    Removing the starter clutch
    1. Remove: Starter clutch bolts "1" NOTE: While holding the generator rotor "2" with the sheave holder "3", remove the starter clutch bolts. Do not allow the sheave holder to touch the projection on the generator rotor. ...

    Introduction
    WARNINGDisc brake components rarely require disassembly. Therefore, always follow these preventive measures: Never disassemble brake components unless absolutely necessary. If any connection on the hydraulic brake system is disconnected, the entire brake sy ...

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