Probably the most frustrating adjustment is the air-door tension. This controls how quickly the air doors on top of the carburetor open as you squeeze into the throttle. This is also where the famous Q-jet bog comes from. Remove the top from the carb as shown here, loosen the set screw (using an Allen wrench), and then turn the tension screw with a flat-blade screwdriver. Opening the door either more or less quickly than the engine needs it will create a bog, and a very small turn of the screw makes a big difference in the opening rate.