Before removing the internal parts of the cylinder head (e.g., valves, valve springs, valve seats), make sure the valves properly seal.
1. Remove:
- Valve lifter "1"
- Valve pad "2"
Make a note of the position of each valve lifter and valve pad so that they can be reinstalled in their original place.
2. Check:
- Valve sealing
Leakage at the valve seat → Check the valve face, valve seat, and valve seat width.
Refer to "Checking the valve seats".
a. Pour a clean solvent "a" into the intake and exhaust ports.
b. Check that the valves properly seal.
There should be no leakage at the valve seat "1".
3. Remove:
- Valve cotters
Remove the valve cotters by compressing the valve spring with the valve spring compressor "1" and the valve spring compressor attachment "2".
Valve spring compressor 90890-04019 YM-04019.
Valve spring compressor attachment 90890-04108.
Valve spring compressor adapter 22 mm YM-04108.
4. Remove:
- Upper spring seat "1"
- Valve spring "2"
- Valve "3"
- Valve stem seal "4"
- Lower spring seat "5"
Identify the position of each part very carefully so that it can be reinstalled in its original place.
