Finding/Confirming TDC: Inquiring Minds Want to Know

[Habitat.pat]

Many years ago I used a motorcycle ignition micrometer that screws in the spark plug hole to verify TDC markings on an engine with a bent timing pointer. The micrometer has a rod that is left loose an left long so when the piston comes up it pushes the rod up leaving it @ the height of TDC. We rotated the piston down, adjusted the micrometer to something like 0.010”, & rotated the crank both directions until the piston touched the micrometer & marked where the pointer lined up with the crank. TDC is half way between the marks. Adjusted the pointer & everything worked fine.

Peace,
Pat