Hey everyone. I got a brain tickler for you. I had a thunder tiger lazy cub. It is a 25 size plane. I put a wankle rotary .30 on it. It was one of the best flying little planes i had. Well I lost signal one flight and it looped into the ground. The only thing hurt was it knoked the rear section of the plane off. I give it to a buddy of mine and he glued it back together. Went together no problem as it was a clean break. He put some triangle stock for reinforcement but you could not even tell it was damaged. Anyway he put a OS 40 la on it. It flew almost the same excpet everytime you would get the nose pointed down, the plane would continue to rotate in a downward motion. In other words the dive would get steeper and steeper with no elevator input. It was like you were holding down elevator. The oddest part about it is that if you pitched the nose up, it would continue upward and the verticle line would get steeper and steeper. I didnt know why it was doing this. I suggested a smaller engine, to knock some weight off the plane. He got a TT 25 and threw on it. The CG is now 30% of the wing chord. It is still doing the same thing. I wouldnt think that this would be a stabilizer incidenc problem because it pitches up AND down. I also wouldnt think that it is a thrust problem. Could somebody shed some light on this subject, as he is about ready to trash the airplane. And I would hate to see that as I know how good it used to fly.