Inspection

Measure the clearance between the valve guide and valve stem. If the limit is exceeded, replace the valve guide or valve, or both. The standard value is 0.02 - 0.05 mm (0.0008 - 0.0020 inch) for intake and 0.04 - 0.07 mm (0.0016 - 0.0028 inch) for exhaust. The wear limit is 0.10 mm (0.004 inch) for intake and 0.15 mm (0.006 inch) for exhaust.