Adjust your throttle servo travel (ATV) so that the carb closes all the way with the trim all the way down then open it up gradually until you get an idle around 2200 or less rpm. Do the same thing on the high end. Increase your servo travel until the carb is fully open. Once the carb is fully open you should get a rpm of 8200 or more with a 18x10 apc prop. You may have to adjust the sub-trim as well.