[Marine One]

Everyone likes to experiment with valve timing, so methods vary depending on what you are trying to accomplish with the iron in your engine. With that said, the following is a very simple procedure to start out with that eliminates countless engine bumps and allot of frustration. Just rotate the engine twice, knocking out half the valves at each stop. Simple, effective and proven.

Identify cyl 1 at TDC (piston at the top of the power stroke with both valves closed). Mark it on the damper.

Rotate engine in direction of standard rotation to remove any lash and stop at your mark. If you overshoot the mark, do not back up, just go around in standard rotation again until you hit it.

Install pushrods and rockers with rocker adjustment screws out (max lash).
Evenly torque your rocker arms to spec.

Gently remove lash between rocker arms and pushrods by slowly tightening the adjustment screws.

At this point without rotating the engine any farther, you should be able to adjust 4 exhaust and 4 intake valves. Your firing order depends on which valves get adjusted.

Rotate the engine in standard rotation again a full 360 degrees, stopping on your “TDC” mark, being mindful not to overshoot the mark..

At this point you should be able to adjust the remaining 4 exhaust and 4 intake valves.

Hope this helps!