Also, it's a kit that I built from planes and stamped balsa. The fuse is "rocket" shaped, but, sets at a downward angle from the wing and tail boom. This makes the rear of the fuse point above the tail boom which is where the motor mounts. So, there is a limit on prop length between fuse rear and tail boom. Maybe this makes sense. I just thought people would accept the fact that I can't put a longer prop on without major reconstruction when I keep telling them that.