Inspect the valve key grooves and the oil seal grooves for chips and wear.
Inspect the valves for burns or cracks.
Inspect the valve stem for burrs and scratches.
Inspect the valve stem. The valve stem must be straight.
Inspect the valve face for grooving. If the groove is so deep that refacing the valve would result in a sharp edge, replace the valve.
Inspect the valve spring. If the valve spring ends are not parallel, replace the valve spring.
Measure the valve spring height. Refer to
Engine Mechanical Specifications. If the valve spring height does not match the specifications, replace the valve spring.