Timing Components: Service and Repair

Valve Timing

1. Turn crankshaft until the No.6 exhaust valve is closing and No.6 intake valve is opening.
2. Insert a 6.350 mm (1/4 inch) spacer between rocker arm pad and stem tip of No.1 intake valve. Allow spring load to bleed tappet down giving in effect a solid tappet.
3. Install a dial indicator so plunger contacts valve spring retainer as nearly perpendicular as possible. Zero the indicator.
4. Rotate the crankshaft clockwise (normal running direction) until the valve has lifted 0.254 mm (0.010 inch). The timing of the crankshaft should now read from 10° before top dead center to 2° after top dead center. Remove spacer.

CAUTION: DO NOT turn crankshaft any further clockwise as valve spring might bottom and result in serious damage.

6. If reading is not within specified limits:
a) Check sprocket index marks.
b) Inspect timing chain for wear.
c) Check accuracy of DC mark on timing indicator.