Note: Before removing the internal parts of the cylinder head (e.g., valves, valve springs, valve seats), make sure that 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".
a. Pour a clean solvent (1) into the intake and exhaust ports.
b. Check that the valves properly seal. There should be no leakage at the valve seat (2).
![](https://motoinstruction.ru/img/yamaha/16/122289.jpg)
2. Remove: valve cotters
Note: Remove the valve cotters by compressing the valve spring with the valve spring compressor (1).
![](https://motoinstruction.ru/img/yamaha/16/122290.jpg)
- Valve spring compressor: 90890-04019