Both the intake and exhaust valve clearances should be set at .013 inch "hot", or at .015 inch "cold". The engine firing order is 1-3-4-2.
To adjust the valve tappet clearance with the engine cold, proceed as follows:
1. Turn the crankshaft clockwise (viewed from front) until the T.D.C. mark on the flywheel is positioned in the middle of the inspection hole and both of the rocker arms of the number 4 (rear) cylinder are "rocking" (exhaust valve closing and intake valve opening). Note: At this point, the number 1 cylinder is approximately at T.D.C on the compression stroke, with both valves closed.
2. With the crankshaft positioned as outlined, loosen the locknuts on the rocker arms for the number 1 cylinder, and with a .015 feeler gauge between the valve stem and the face of the rocker arm, turn each adjusting screw until the correct clearance is obtained. Tighten locknuts and recheck clearance.
3. Turn the engine crankshaft clockwise approximately 1/2 of a turn until the number 2 cylinder rocker arms are "rocking" and adjust the valve tappet clearances of the number 3 cylinder.
4. Turn the crankshaft clockwise another 1/2 of a turn until the number 1 cylinder rocker arms are "rocking" and adjust the valve tappet clearances for the number 4 cylinder.
5. Turn the crankshaft clockwise another 1/2 of a turn until the number 3 cylinder rocker arms are "rocking" and adjust the valve tappet clearances for the number 2 cylinder.