Thank you NormK for your suggestion. As this is not my machine, any change from original setup will have to be discussed with the owner of the mower. In the meantime, I'll reset the electronics back to their original positions again in the morning so it's at least sort of running. Reading information from Max, it may be that the points are worn as they didn't seem to fully close and seemed to open well before expected at 1/8" (3-4mm) before TDC.
