Thanks for this valuable information. I just want to add that I did add down thrust to the engine by using 3 relatively thick washers in between mount/firewall screws. The engine looks very tilted downwards and when I trim for level flight at high throttle and bring the throttle back quickly the plane would nose up sharply and climb until the speed drops .From what I gather from the responses it looks like that it is wing stabilizer incidence problem which I don’t know how it came about because I did follow the plan correctly during construction. I have built several kits before and all fly great. Do you check the incidence of the stabilizer as well as the wing?