Carburetors are technology that since fuel injection have become kind of a relic to the latest generation of car builders. That doesn’t mean that the tried and true carbureted fuel delivery system isn’t a viable option anymore. If anything, high performance enthusiasts would rather use a carb for their top end machines. Sadly, Carb tuning is quickly becoming a lost art.

That’s why Pace Performance of Boardman, Ohio recommends a series of steps in making sure that your performance carburetor is set to optimum adjustments, allowing for your performance motor to run the way that it should.

The first step, naturally is to set the idle speed screw, allowing for vacuum to be further adjusted.

The idle screw should be set to where 1/8″ of the carburetor’s transfer slot above the throttle body butterfly plate is visible, and if not then the carburetor will run off of its main circuit and will not be able to be calibrated to a correct idle speed. During this procedure, it’s also important to remember that the choke must be completely open and that the carburetor’s fast idle mechanism must be completely disengaged.

With these carburetors from Pace, there are two idle speed adjustments; the lower screw makes contact with a shaft that helps it to control a motor’s idle speed at high cruising speeds, while the normal idle speed screw controls engine speed once the motor is warmed-up.

Assuming that the engine is now at running temperature, make sure that the mixture screws are turned 2-3 turns equally until an optimum vacuum reading can be spotted on a vacuum gauge connected to a source on the motor’s intake. The highest reading is the one that should be sought after by the engine builder.

The carburetor setup featured here is an Edelbrock/AFB style assembly, but Pace also notes that this carburetor is very similar in construction to a Holley. If your aftermarket carburetor of choice is either of these, then definitely make sure to check out Pace Performance to see if they can offer you the perfect setup!