Checking The Valve Springs

VALVES AND VALVE SPRINGS

4. Lap:
 • Valve face
 • Valve seat
NOTE:
After replacing the cylinder head or replacing the
valve and valve guide, the valve seat and valve
face should be lapped.
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a. Apply a coarse lapping compound “a” to the
   valve face.                                               h. Install the valve into the cylinder head.
ECA13790
                                                             i. Press the valve through the valve guide and
CAUTION:
                                                                onto the valve seat to make a clear impres-
Do not let the lapping compound enter the                       sion.
gap between the valve stem and the valve                     j. Measure the valve seat width “c” again. If the
guide.                                                          valve seat width is out of specification, reface
                                                                and lap the valve seat.

b. Apply molybdenum disulfide oil onto the
   valve stem.                                               ▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
c. Install the valve into the cylinder head.                 EAS24310

d. Turn the valve until the valve face and valve             CHECKING THE VALVE SPRINGS
   seat are evenly polished, then clean off all of           The following procedure applies to all of the
   the lapping compound.                                     valve springs.
NOTE:                                                        1. Measure:
For the best lapping results, lightly tap the valve           • Valve spring free length “a”
seat while rotating the valve back and forth be-                Out of specification → Replace the valve
tween your hands.                                               spring.

                                                                        Free length (intake)
                                                                         39.73 mm (1.56 in)
                                                                        Limit
                                                                         37.74 mm (1.49 in)
                                                                        Free length (exhaust)
                                                                         39.73 mm (1.56 in)
                                                                        Limit
                                                                         37.74 mm (1.49 in)

e. Apply a fine lapping compound to the valve
   face and repeat the above steps.
f. After every lapping procedure, be sure to
   clean off all of the lapping compound from the
   valve face and valve seat.
g. Apply Mechanic’s blueing dye (Dykem) “b”
   onto the valve face.

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