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:

    Storage
    Short-term Always store your motorcycle in a cool, dry place and, if necessary, protect it against dust with a porous cover. NOTICE Storing the motorcycle in a poorly ventilated room or covering it with a tarp, while it is still wet, will allow water and humidity to seep in and ...

    Lubrication diagrams
    Clutch push lever Main axle Drive axle Crankshaft Oil filter Oil pump assembly Oil strainer To cylinder head Camshaft Crankshaft Main axle Drive axle ...

    Checking the clutch housing
    1. Check: Clutch housing dogs "1" Damage/pitting/wear  Deburr the clutch housing dogs or replace the clutch housing. NOTE: Pitting on the clutch housing dogs will cause erratic clutch operation. 2. Check: Bearing Damage/wear Replace the bearing and clutch housin ...

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