What I meant by a hotter plug, and I'm sure a bunch of guys will chime in on it, was this. I used to have an old saito, I think it was a 56 that ran like yours. I couldn't get it to run reliably for nothing. At wits end with it, I figured I would try what an old guy at the field kept telling me which was to try a hot two stroke plug. It helped immensely. I flew it like that for a number of years. It turned out to be a descent little engine. Weird, huh? It was the only four stroke that I ever did that with. Have you asked around in the glow forums?