My car is running entirely too rich. It svery strong. My dad says he was gonna adjust for me but hasnt yet (that was a month ago) I know how to adjust it. Theres three screws. Air,Fuel, and idle.

Its idles at about 1100 rpms but i need to know how you know when a carb is adjusted right. I want to learn to do this as it has had to be done to the car periodically