Tools Required

Caution: Wear safety glasses in order to avoid eye damage.

1. Clean the valve stems and cylinder heads on a buffing wheel.
2. Clean the following components in cleaning solvent:

•	The valve stem keys (1)

•	The valve spring cap (2)

•	The valve spring (3)

•	The cylinder head

3. Dry the components with compressed air.



4. Use the J 8089 to clean the carbon from the cylinder head combustion chambers.

Do not scuff the combustion chambers.

5. Inspect the cylinder head for the following:

•	Damage to the gasket surfaces

•	Damage to the threaded bolt holes

•	Burnt or eroded areas in the combustion chamber

•	Cracks in the exhaust ports and combustion chambers

•	External cracks in the water chamber

•	Restrictions in the intake or exhaust passages

•	Restrictions in the cooling system passages

•	Rusted, damaged, or leaking core plugs




6. Measure the cylinder head for warpage with a straight edge and feeler gauge.

•	A cylinder head block deck with warpage in excess of 0.10 mm (0.004 in) within a 152.4 mm (6.0 in) area must be repaired or replaced.

•	A cylinder head exhaust manifold deck with warpage in excess of 0.05 mm (0.002 in) must be repaired or replaced.

•	A cylinder head intake manifold deck with warpage in excess of 0.10 mm (0.004 in) must be repaired or replaced.




7. Use the J 9666 in order to measure the valve spring.

Replace the valve spring if the valve spring tension is less than 338 N (76 lb) at 43.2 mm (1.70 in).




8. Inspect the valve springs for squareness.



9. Valve stems (1) with excessive guide (2) clearance must be repaired or replaced.



10. Measure the valve stem-to-guide clearance.

Excessive valve stem-to-guide clearance may cause an excessive oil consumption and may also cause a valve to break. Insufficient clearance will result in noisy and sticky functioning of the valve and will disturb the engine assembly smoothness.

10.1.

Clamp the J 8001 on the exhaust port side of the cylinder head.

10.2.

Locate the dial indicator so that the movement of the valve stem from side to side, crosswise to the cylinder head, will cause a direct movement of the dial indicator stem.

The dial indicator stem must contract the side of the valve stem just above the valve guide.

10.3.

Drop the valve head about 1.6 mm (0.063 in) off the valve seat.

10.4.

Use light pressure and move the valve stem from side to side in order to obtain a clearance reading. Refer to Engine Mechanical Specifications .