Valve: Service and Repair
1. Grind the valve enough to remove pits and carbon.
2. Check that the valve is ground to the correct valve face angle.
Valve face angle: 44.5°.
3. After grinding valve, check the valve head margin thickness.
Standard margin thickness: 1.000 mm (0.0390 in).
Minimum margin thickness: 0.500 mm (0.0200 in).
4. If the margin thickness is less than minimum, replace the valve.
5. If valve stem tip is worn, resurface the tip wit a grinder or replace the valve.
NOTE: Do not grind off more than minimum.