Service Manual, General Motors 4.3L Engine (TP ... - Kohler Power

6-104 Marine/Industrial 4.3L Engine
156173
6. Inspect the valve contact surface for the following:
• Undersized margin (1)
• Pitted surfaces (2)
• Burnt or eroded areas (3)
• Acceptable edge (margain) (4)
Valves with excessive damage must be replaced.
Minor imperfections of the valve or valve seat may be
repaired.
7. Reconditioning of the valves and valve seats:
• The valves must seat perfectly for the engine to deliver
optimum power and performance.
• Cooling the valve heads is another important factor.
Good contact between each valve and valve seat in the
cylinder head is necessary to insure that the heat in the
valve head is properly carried away.
• Regardless of what type of equipment is used, it is
essential that the valve guide bores are free from carbon
or dirt in order to ensure the proper centering of the pilot
in the valve guide.
The valve seats should be concentric to within 0.05 mm
(0.002 in) total indicator reading.
• Reface pitted valves on a valve refacing machine in order
to ensure the correct relationship between the valve head
and the valve stem.
Replace the valve if the valve stem is excessively worn
or warped.
Replace the valve if the edge margin (4) of the valve
head is less than 0.79 mm (0.031 in) thick after grinding.
• Several different types of equipment are available for
reconditioning valves and valve seats. Follow the
equipment manufacturer’s recommendations for
equipment use to attain the proper results.
Cylinder Head Assemble
Tools Required
J 8062 Valve Spring Compressor
J 42073 Valve Stem Seal Installer
Important: The exhaust valve oil stem seal has the letters EX (1)
molded into the top of the seal. The exhaust valve oil stem seal
material is brown in color (2) with a white stripe (3) painted onto
the outside diameter of the seal, or the material may be red in
color (2) with no paint stripe. The intake valve oil seal is black in
color.
1. Assemble the valve into the proper valve guide.
2. Select the proper valve stem oil seal for the specific valve
guide.
3. Lubricate the valve stem oil seal and the outside diameter of
the valve guide with clean engine oil.
480558
2000 Marine/Industrial