Originally Posted by CARS II

Mike
I did as you suggested, I inserted a marked dowel through the spark plug hole to ID TDC but found the piston stopper technique more accurate. This been the first time for me timing an engine I wanted to be as accurate as possible, I also confirmed that the piston stopper technique is accurate by checking that the piston was at TDC via the spark plug hole.

From now on this is how I'm going to time all my future gas engines.