Fuel for idle and low speed operation is drawn from the fuel bowl (A), through fuel passage (B), past main metering jet (C), up channel and through idle jet (D) and is mixed with air from idle air bleed (E). This relatively rich mixture passes through the economizer (F). Part of it then passes into the carburetor bore through idle port (G) and the balance enters the bore past the idle adjustment screw (H). Clockwise rotation of the idle adjustment screw, which controls the amount of uel air mixture, leans the mixture, while turning the screw counterclockwise richens it. Do not attettempt to remove the idle air bleed (E) and economizer (F).