What manual suggested the 11x7 for break in? I use the OS 46AX which is more powerful than the LA 40 and the recommended breakin prop is 10X6. My regular flights after that have been made with the 11x6. I have a buddy who uses an 11x7 on his identical plane. It seems to fly ok but my LHS thinks that prop is a bit much for the motor...however, the manual does include this size as a recommended one.