I've used a "calibrated thumb" to find the compression stroke for over 60 years. A couple of corks allow you to do a one man timing job on an engine with a foot starter since I don't know of anyone without some primate DNA with arms long enough to sit in the cab and put his thumb over a spark plug hole.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!