Establishing top dead center in an outboard hs easy if the spark plug is over the top of the piston. First you need a place on the block under the edge of the flywheel to use as a reference. If nothing stands out, make a mark with a cold chizle. Next thread a bolt into the spark plug hole far enough to keep the motor from turning over. (A hacksaw cut across the bolt will relieve compression – or a pass with a Dermal cut off wheel.) Turn the flywheel in one direction until it stops. Make a mark on the flywheel above your reference mark with a felt tip pen. Turn the flywheel backwards until it stops. Make another mark. Top dead center is between these two marks, equidistant from each. . . . 😀
Garry
