Adjusts the fuel/air mixture on the main (high-speed) circuit of the IAME KA100 or X30's carburetor, controlling fuel delivery from mid-throttle through wide-open throttle. Turning it in leans the mixture, turning it out richens it — tuners typically work in small fractions of a turn since it affects the whole top end.
*NOTE: Does not include spring, washer or o-ring
