Valve: Adjustments

Checking The Valve Clearance.

NOTE: Cylinder head removed. .

NOTE: Before the valve clearance can be checked, the camshafts and cam followers must be removed. Service and Repair.

The valve clearance is checked relative to the working range of the cam follower. The checking values for the valve clearance are 19.5 ± 0.05 mm (0.768 ± 0.002 in) minimum, and 20.5 ± 0.05mm (0.807 ± 0.002 in) maximum. The setting values are 20.0 mm (0.787 in) minimum, 20.4 mm (0.803 in) maximum, with a nominal value of 20.2 mm (0.795 in). The valve clearance is equivalent to the distance between the end of the valve stem and the camshaft bearing seat.

Check the valve clearance using tool 8393 753 as follows.
Place the measuring head across two of the camshaft bearing seats.
Line up the instrument to read the depth to the end of the valve stem.
Check that when the instrument is displaying the maximum depth reading of 20.5 mm (0.807 in) it actually reaches the end of the valve stem, which will be confirmed by the fact that the measuring head does not make contact with the bottom of the bearing seat closest to the instrument. Thereafter, check that the contact point of the instrument does not touch the end of the valve stem when showing the minimum depth reading of 19.5 mm (0.768 in).

The valve clearance is correct when the reading obtained is between the minimum and maximum values. If the valve clearance deviates from the specified checking values, adjustment must be made to the valve stem or the valve seat:
- If the value is lower than the minimum value, the length of the valve must be reduced.
- If the value is greater than the maximum value, the valve seat must be milled.
The nominal value for adjusting the position of the valve is 20.2 mm (0.795 in).