Valve Adjustment Procedures

Valve clearances should be checked and, if necessary, adjusted every 12,500 miles. Clearances for 4-120 engines should be .004 inch for intake valves and .010 inch for exhaust valves. Clearance for 4-134 engines should be .008 inch for intake valves and .012 inch for exhaust valves. Before attempting to check or adjust valve clearances, allow engine to cool.

Valve Arrangement

FRONT TO REAR
As viewed from flywheel end of engine (cylinder No. 1), intake valves are located on the left side of the cylinder head and exhaust valves are located on the right side of the cylinder head.

Fig. 4 Valve clearance adjustment.:

Fig. 5 Valve clearance adjustment.:

Valves, Adjust
1. Disconnect necessary spark plug high tension leads, hoses and electrical connectors noting position for installation, then remove valve cover.
2. Rotate crankshaft as necessary to position exhaust valves as shown in Figs. 4 and 5, then check and if necessary, adjust valves as shown.
3. Install valve cover, then reconnect electrical connectors and hoses in positions noted during removal.