Sounds like spark interference to me. Have you tried turning off each mag to see if you can further isolate the problem? Also, if you can manage to look at your engine in the dark with the engine ticking over, you may be able to see a spark from a leaky ignition wire. Might be a good idea to move the spark wires around (temporarily and without the engine running) then start up and see if there's a difference. Easy to use harness testers are available from Spruce, etc, as well, as a last resort. Kinda pricey, but at least you have a nice tool you can loan to your friends. Mike, N93381 "Betty"
