VALVE SEAT INSPECTION/REPAIR

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1. Measure the contact width of the valve face and the valve seat using the valve lapping compound.

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• If it is not within the specification, resurface the valve seat using the 45° valve seat cutter.

Standard valve seat contact width

1.37—1.84 mm {0.0540—0.0724 in}

Valve seat angle

45°

2. Verify that the area where the valve seat contacts the valve face is centered.

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• If the seating position is too high, correct the valve seat using a 70° (IN) 70°(EX) valve seat cutter and a 45° valve seat cutter.

• If the seating position is too low, correct as follows:

― IN: Correct the valve seat using a 20° valve seat cutter and then using a 45° valve cutter.

― EX: Correct the valve seat using a 45° valve seat cutter.

3. Inspect the valve seat for sinkage. Measure the protruding length (dimension L) of the valve stem using a valve of standard length.

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• If it is not within the specification, replace the cylinder head.

Standard valve seat sinkage amount (Dimension L)

IN: 48.93—50.17 mm {1.927—1.975 in}

EX: 48.87—50.11 mm {1.925—1.972 in}