well the idle needle and high speed needle are both at rich, very rich. I simply won't go above half throttle. I have a MAS 11x6 on it which is one of the recommended prop sizes. I also have a 10x7 waiting in the wings but I don't really see any need to install it. With the idle bar plug it's a power house, without it a paper weight. I'm currently reading the suggested post above to see if I can glean any information out of it.