Need a littlel lighter load than a 26x11 carbon prop for it to wind up, try a 26x10 menz s, will let it wind up a little better. I even tried a mejzlik 24x12 3 blade, and was getting 6100rpm with that prop, but it likes the 26x10 a little better to me. My engine is well broke in, a lot depends on how much time is on the motor.