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:

    Indicator and warning lights
    Indicator and warning lights Neutral indicator light"" Turn signal indicator light"" High beam indicator light"" Engine trouble warning light"" Coolant temperature warning light"" Turn signal indicator light"" This indicator light flashes when the turn signal switch is pushed t ...

    Checking the spark plug
    The spark plug is an important engine component, which is easy to check. Since heat and deposits will cause any spark plug to slowly erode, the spark plug should be removed and checked in accordance with the periodic maintenance and lubrication chart. In addition, the condition of the ...

    Preparation for removal and disassembly
    1. Before removal and disassembly, remove all dirt, mud, dust and foreign material. 2. Use only the proper tools and cleaning equipment. Refer to "SPECIAL TOOLS" on page 1-8. 3. When disassembling, always keep mated parts together. This includes gears, cylinders, pistons and other part ...

    2021 Copyright www.yam-r125.net |