Inspection

Measure the clearance between the valve guide and valve stem should be 0.02 - 0.05 mm (0.0008 - 0.0020 inch) for intake or 0.05 - 0.09 mm (0.002 - 0.0035 inch) for exhaust and, if the clearance exceeds 0.10 mm (0.004 inch) for intake or 0.15 mm (0.006 inch) for exhaust, replace the valve guide or valve, or both.