Commit,

That negative stance while on the ground will certainly cause the airplane to "stick" and then suddently jump into the sky. As for the OS... getting 12800 with an 11/7 is about right. You are not running enough prop for that engine. You need to start with an 11/8 and go up to probably 11/10 and see which way it flies best. With the bigger pitch, the engine will turn slower but give you more torque. This is where you just need to fly the plane and see what you like. You can get an offset header so that you can run the header/pipe under the wing. The pipe will give you about 1000 RPM. Before I go thru that, I would probably simply bolt on an OS .91 FX. 1/3 more cubic inches and 1oz less weight. Should make the plane REALLY haul and go vertical without having to go with the pipe setup. Just a thought... have fun.

Dan

Carolina Custom Aircraft