I agree I am running a 14''- 8 MK prop with 20% Powermaster cline regulator it seems to be the one it likes the best. I have tried the APC in larger sizes but liked the pick up with the MK. I going to get a larger Graupner prop like a 15''-4 and run some cool power 30% and see how it likes it next. I got a great deal on a case price on the cool power and could not pass it up.