My old girls timing is off so I've bought a dial gauge and am attempting to do the 0.5mm at 11 degrees BTDC thing.
But, my harmonic balancer seems to have 6 (yes six) timing marks on it ?! Its a gear drive engine (no idea on its history) I'm fairly sure the first one is TDC, but the rest are a bit of a mystery and why there are so many. I've hunted high and low in forums and the interwebs to no avail. Anyone got any clues as to which is which ? Or perhaps another method to measure 10 or 12 degrees BTDC maybe.