LJ, It was me who uses a buzzer for ignition timing. These are purpose made items specifically made for magneto timing. They use your magneto points as a switch to activate buzzer, one crocodile clip goes to earth, other goes to points centre screw. Can,t be much current going thru mag as they only use a 1.5 volt AA battery.These were available from independant ignition supplies, but cant find them on there website now. The price is rather expensive, but as I mentioned earlier I borrow mine from a mate who services tiger moth planes, now these things have to dead on and if you damage the mags on these they cost a small fortune to repair being BTH magneto type . I know he has used this tool for years with no problems & if I can find out who made it I,ll post it here on this forum. I have used the old fag paper method though you can get some good results but there is always the doubt but not with a buzzer as you can rotate engine after you have timed it and check on a timing disc with auto advance open till you hear buzzer then check disc, 34 degrees BTDC (regardless of piston compression ratio). best regards G/F DAVE....