Thanks Dave, when I was fighting with the other 912, I noticed it had what seems like the same kind of shake at around those rpms. I never did fly that engine though, but noticed the shake when slowing down from a high rpm on the ground. I weighed all the floats from both engines and they were all lighter then the maximum. I think the heaviest one was 3.1, and at least one was 2.8 grams. My EGTs are pretty low on the engine now though, just monitoring 2, and not sure how accurate they are, but one is about 1050, the other one is around 1200. I'll look at the plugs and see how black they look. JImChuk