Valve: Testing and Inspection

1. Clean valves.
a. Using a gasket scraper, chip off any carbon from the valve head.
b. Using a wire brush, thoroughly clean the valve.





2.. Inspect valve stems and guide bushings.
a. Using a caliper gauge, measure the inside diameter of the guide bushing.
Bushing inside diameter:
6.010-6.030 mm (0.2366-0.2374 in.)






b. Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter:
Intake:
5.970-5.985 mm (0.2350-0.2356 in.)
Exhaust:
5.965-5.980 mm (0.2348-0.2354 in.)
c. Subtract the valve stem diameter measurement from the guide bushing inside diameter measurement.
Standard oil clearance:
Intake:
0.025-0.060 mm (0.0010-0.0024 in.)
Exhaust:
0.030-0.065 mm (0.0012-0.0026 in.)
Maximum oil clearance:
Intake:
0.08 mm (0.0031 in.)
Exhaust:
0.10 mm (0.0039 in.)
If the clearance is greater than maximum, replace the valve and valve guide bushing.





d. Check the valve overall length.
Standard overall length:
Intake:
100.60 mm (3.9606 in.)
Exhaust:
100.45 mm (3.9547 in.)
Minimum overall length:
Intake:
100.1 mm (3.941 in.)
Exhaust:
100.0 mm (3.937 in.)
If the overall length is less than minimum, replace the valve.





3. Inspect and grind valves.
a. Grind the valves enough to remove pits and carbon.
b. Inspect that the valve is ground to the correct valve face angle.
Valve face angle: 44.5°





c. Inspect the valve head margin thickness.
Standard margin thickness:
0.8-1.2 mm (0.031-0.047 in.)
Minimum margin thickness:
0.5 mm (0.020 in.)
If the margin thickness is less than minimum, replace the valve.