Yamaha YZF-R125 Service Manual: Removing the valves

The following procedure applies to all of the valves and related components.

NOTE:

Before removing the internal parts of the cylinder head (e.g., valves, valve springs, valve seats), make sure the valves properly seal.

1. Check:

  • Valve sealing Leakage at the valve seat Check
    the valve face, valve seat, and valve seat width.

    Refer to "CHECKING THE VALVE SEATS" on page 5-20.

a. Pour a clean solvent "a" into the intake and exhaust ports.

b. Check that the valves properly seal.

NOTE:

There should be no leakage at the valve seat "1".

Removing the valves


2. Remove:

  • Valve cotters "1"

NOTE:

Remove the valve cotters by compressing the valve spring with the valve spring compressor and the valve spring compressor attachment "2".


Removing the valves


3. Remove:

  • Upper spring seat "1"
  • Valve spring "2"
  • Valve "3"
  • Valve stem seal "4"
  • Lower spring seat "5"

NOTE:

Identify the position of each part very carefully so that it can be reinstalled in its original place.

Removing the valves


    Valves and valve springs
    ...

    Checking the valves and valve guides
    The following procedure applies to all of the valves and valve guides. 1. Measure: Valve-stem-to-valve-guide clearance Out of specification Replace the valve guide. Valve-stem-to-valve ...

    Other materials:

    Installing the relay arm
    1. Lubricate: Spacers Bearings Oil seals Bolts (unthreaded shaft portion only) 2. Install: Bearing "1" (to the relay arm) Oil seal "2" (to the relay arm) 3. Rear shock absorber assembly 4. Relay arm 5. Connecting arm A. Left side B. Right side ...

    Checking the ignition coil
    1. Check: Primary coil resistance Out of specification  Replace. a. Disconnect the ignition coil connectors from the ignition coil terminals. b. Connect the pocket tester ( × 1) to the ignition coil as shown. Positive tester probe red/white "1" Negative tester probe orange ...

    Checking and lubricating the brake and clutch levers
    Brake lever Brake lever Clutch lever Clutch lever The operation of the brake and clutch levers should be checked before each ride, and the lever pivots should be lubricated if necessary. Recommended lubricants:Brake lever: Silicone grease Clutch lever: Lithium-soap ...

    2021 Copyright www.yam-r125.net |