Hi Colin I agree that chewed teeth could send the signal wonky but surely you would replace that sort of damaged part before flight. In any case that is not really the issue. A wonky signal to the tacho from a tooth counter will never kill your ignition as it's completely independent of it. Using a tacho with or without diodes off the coil primary will always carry that risk even it is is small as you correctly say. I like medieval points also because I understand them and can easily replace them in the field at remote Australian airports if I need to. Each to his own circumstance I guess. Long live the diode :-)
John Martindale 29 Jane Circuit TOORMINA NSW 2452 AUSTRALIA phone: 61 2 66584767 (H) 61 2 66869075 (W) mobile: 0403 049990 email: johnja...@optusnet.com.au web: www.members.optusnet.com.au/johnjanet/Martindale.htm > ....And so the story goes that as many people as we have here on the net, we > have experiences.................