i have an11x6 that i purchased at the LHS for my OS 46. i was told that was what i am supposed to use for it. i think an 11x8 would be too much for my 40. now, the directions told me to use a 10x5, or 10x6 for break-in.  i ended up getting a 10x6. i think because i was thinking it would be ok to fly with that prop also. sound good to anyone else?