88238A 4 Mercury GROUND STRAP ASSEMBLY, TRIM COVER SCREW

Table 1
Required Tools
Tool Part Number Part Description Qty
A 166-7441 Valve Seat Extractor 1
9S-3095 Puller Handle 1 Start By:
Remove the inlet valves and the exhaust valves. Refer to Disassembly and Assembly, "Inlet and Exhaust Valves - Remove and Install".
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Illustration 1 g00937142
Typical example
Use the Tooling (A) in order to remove valve seat inserts from the cylinder head.
Repeat the procedure for the remaining valve seat inserts. Note: When new valve seat inserts are installed, new valves and new valve guides must be installed.
Remove the valve guides. Install partially finished valve guides. Refer to Disassembly and Assembly, "Inlet and Exhaust Valve Guides - Remove and Install". Installation Procedure
Table 2
Required Tools
Tool Part Number Part Description Qty
B 157-3716 Valve Seat Driver (Exhaust) 1
157-3717 Valve Seat Driver (Inlet) 1
C 157-3720 Valve Seat Cutter 1
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Note: The inserts for the inlet valves are a larger diameter than the exhaust valve inserts.
Use the partially finished bore of the valve guide as a pilot bore in order to machine a recess for a new valve seat. Refer to the Specifications Manual, "Cylinder Head Valves" for the required dimensions of the recess for the valve seat. Remove all debris from the cylinder head ports and passages. Note: If the cylinder head has been previously ground then the bottom face of valve seat must be ground in order to ensure that the valve seat will be installed correctly into the cylinder head. A 30 degree chamfer must be machined to the outer edge of the valve seat after the back face of the valve insert has been ground to the correct dimensions. The 30 degree chamfer must be within the tolerance of 0.91 mm (0.036 inch) to 1.3 mm (0.051 inch). Also, the chamfer must be inclined to the vertical face of the valve insert.
Repeat the Step 1 for all of the appropriate valve seats. Note: Do not apply any lubricant before the new valve seat insert is installed into the cylinder head.
Illustration 2 g00937187
Typical example
Put the valve seat insert in position. Carefully tap the valve seat insert in order to start the installation. Use the Tooling (B) to seat the valve seat insert in the cylinder head.
Repeat the procedure for the remaining valve seat inserts. Note: Refer to the Specifications Module for more information on the valve seat inserts.
After installing the valve guides and valve seat inserts, the valve guides must be reamed and the valve seat inserts must be cut to the finished diameter. The valve guides and valve seat inserts are cut and reamed in one operation. This procedure ensures the concentricity of the valve seat to the valve guide in order to create a good seal. Refer to Specifications, "Cylinder Head Valves" for the finished diameter of the valve guides and valve seat inserts.
Position the Tooling (C) into the valve guide. Carefully turn the handle in a clockwise direction and gradually move the reamer into the valve guide until the valve guide is reamed to the finished size.
Continue to turn the handle in a clockwise direction in order to cut the valve seat insert. Remove the minimum amount of material in order to ensure a good valve seat. Keep the valve seat as narrow as possible.
Remove Tooling (C). Clean the debris from the valve guide and the valve seat.
Repeat Step 6 to Step 8 in order to cut all of the appropriate valve seats. End By:
Install the inlet valves and the exhaust valves. Refer to Disassembly and Assembly, "Inlet and Exhaust Valves - Remove and Install".