The idle mixture screws are on the side of the primary fuel bowl. One side is close to that fuel level plug. With the engine idleing turn each screw in slowly till the engine starts to slow down. Then back it out enough go back to the faster idle, about 1/4 turn. Then adjust your idle speed to about 600 rpm if you have a tach. or about 750 if is auto trans. If you don,t have a tach set it where it sounds good & is comfortable.
