How to Tune an Edelbrock 1406 Carburetor

by John Stevens J.D.

The Edelbrock 1406 is a four-barrel "Performer Series" carburetor fitted with an electric choke. Although Edelbrock carburetors are designed to work right out of the box, variations in temperature and altitude can affect the carburetor's performance. To compensate for these variables, even a new 1406 should be tuned up. Fortunately, doing so is a fairly straightforward process and no disassembly is required.

Locate the two air/fuel mixture screws and the idle speed screw, also known as the air screw. Note that three metal ports extend from the front of the carburetor, just below the "Edelbrock" emblem. On each side of the middle port is a standard screw. These two screws are the air/fuel mixture screws. The idle speed screw is a standard screw located on the front of the bottom of the throttle linkage. The throttle linkage is located on the driver's side of the carburetor.

Start the engine and allow it to warm.

Adjust the idle speed screw until the desired idle speed is reached, as noted by the vehicle's tachometer. Consult the vehicle's specifications manual if the speed will be set to the engine's stock setting. Turn the screw in a clockwise direction with a standard screwdriver to increase the engine speed, and in a counterclockwise direction to decrease the engine speed.

Turn one of the air/fuel mixture screws in either direction with a standard screwdriver only until the maximum engine speed is reached.

Lower the engine's idle speed to the desired level by turning the idle speed screw in a counterclockwise direction if the idle speed has increased by more than 40 RPM.

Turn the remaining air/fuel mixture screw in either direction only until the maximum engine speed is reached.

Lower the engine's idle speed to the desired level by turning the idle speed screw in a counterclockwise direction.

Adjust each air/fuel mixture screw in small increments until the highest idle speed is reached.

Turn both air/fuel mixture screws in a counterclockwise direction in small, identical increments until the idle speed decreases by 20 RPM.

Lower the engine's idle speed to the desired level by turning the idle speed screw in a counterclockwise direction.

Items you will need

References

About the Author

John Stevens has been a writer for various websites since 2008. He holds an Associate of Science in administration of justice from Riverside Community College, a Bachelor of Arts in criminal justice from California State University, San Bernardino, and a Juris Doctor from Whittier Law School. Stevens is a lawyer and licensed real-estate broker.