Plowboy:

I am running the Evolution .46 on my Kadet LT40, and have VERY good luck with the Master Airscrew 11x6, and I am presently running a Top Flite power prop in 11x7.5, which really works well on my engine. A lot of guys will tell you that the 11x6 or 11x7 prop is "too much" prop for your engine, but that is just not true with the Evo's. I've been running the 11x7.5 for almost three months now, and the performance is great. I would start with an 11x6 and see what results you get, and go from there.