## Cylinder Head

#### Valve Seat Insert Reconditioning

6-25

Valve seat Insert Replacement

1. Arc weld the rod at several points. Be careful not to damage the cylinder head.

1. Allow the rod to cool for a few minutes. This will cause the valve seat to shrink.

1. Strike the rod and pull it out.

1. Carefully clean the valve seat press-fit section on the cylinder head side.

1. Heat the press-fit section with steam or some other means to cause expansion. Cool the valve seat with dry ice or some other means.

1. Insert the press-fit section into the valve seat horizontally.

Standard fitting interference:

0.06 mm – 0.08 mm (0.0024 in – 0.0031 in)

Valve Seat Insert Correction

1. Remove the carbon from the valve seat insert surface.

1. Use a valve cutter to minimise scratches and other rough areas. This will bring the contact width back to the standard value. Remove only the scratches and rough areas. Do not cut away too much. Take care not to cut away unblemished areas of the valve seat surface.

Valve seat angle degree:

89.5°

1. Apply abrasive compound to the valve seat insert surface.

1. Insert the valve into the valve guide.

1. Turn the valve while lapping it to fit the valve seat insert.

1. Check that the valve contact width is correct.

1. Check that the valve seat insert surface is in contact with the entire circumference of the valve.

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