Just put Evolution 61 on a Seagull Decatlon 40 plane and i am very dissatisfied with the performance. I tried a 11 X prop turning 13,300 RPM and the plane had very little power or speed. I then tried a 12 X 6 prop that was turning 12,600 RPM. It was better but still top speed was slow ans vertical climb was pretty limited. I am assuming this is a prop problem but does anybody have any idea on what to try? thanks