loosten the four bolts holding the boom to fuse, dont forget the little set screws. d/c rudder link and support boom. Push boom forward to get the drive belt out and lok at the boom. any damage to the boom end could cause binding. Make sure the belt is twisted in the right direction and pull boom tight. check movement if ok tightern all down. I ahd a major crash with my venture put a new boom and blades on and she runs fine