How to Adjust an Edelbrock 1406 Carb

by Ryan Hotchkiss

american v8 engine image by kenmo from Fotolia.com

Adjusting an Edelbrock 1406 carburetor is a relatively straightforward engine maintenance task. Known for its simplicity, durability and performance, the Edelbrock 1406 requires no electronic equipment and no understanding of vacuum lines. In other words, adjusting an Edelbrock 1406 carburetor requires no prior knowledge of carburetors. You can adjust an Edelbrock 1406 carburetor to prevent it from running too rich -- that is, too much fuel versus air -- or from running with a mixture that's too lean on fuel.

Step 1

Fire the engine and give it time to warm to idle temperature. Locate the choke -- found on the top of the carburetor -- and make certain it is open entirely. It must be opened completely for you to set the mixture screws.

Step 2

Adjust the air screw found between the two mixture screws to an idle speed of between 700 revolutions per minute and 900, depending on your engine, with the flat-head screwdriver. Clockwise turns increase rpm, while counterclockwise turns reduce the speed.

Step 3

Seat the flat-head screwdriver in the right mixture screw. Turn the mixture screw clockwise while counting each complete turn until the mixture screw butts up against the body of the carburetor. Write down the number of complete turns. Re-adjust the air screw until the idle of the engine once again falls between 700 and 900 rpm.

Step 4

Seat the flat-head screwdriver in the left mixture screw. Turn the mixture screw clockwise while counting each complete turn until the mixture screw butts up against the body of the carburetor. Write down the number of complete turns. Re-adjust the air screw until the idle once of the engine again falls between 700 and 900 rpm.

Step 5

Take the average between the complete turns of the two mixture screws. For example, if the right mixture screw required three complete turns and the left required four, the average is 3 1/2.

Step 6

Back both mixture screws off the body of the carburetor -- turning them counterclockwise with the flat-head -- the average of their original two settings. Re-adjust the air screw so the idle once again falls between 700 and 900 rpm.

References

Things You'll Need