Rochester Quadrajet Carburetor Idle Mixture Screws

Rochester Quadrajet Carburetor Idle Mixture Screws 16-139

1 Review(s)

Your Price: $6.95

Thread = 4M x .50 Overall length = 1.266 Shaft = .9240". Compare overall length & the taper at the end.

Part Number: 16-139

Availability: In Stock

Included *

Spring (66D83)

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Rochester Quadrajet Idle Mixture Screw. Sold individually, you'll need two. Spring included.

There is no conversion chart between carburetor numbers and idle mixture screws. To be sure you are getting the right screw, compare the size listed and the way the taper looks in the photo, to the original screw.

SPECS:

Thread = 4M x .50
Overall length = 1.266
Shaft = .9240"

AMONG OTHERS MAY FIT:

Rochester Quadrajet
Rochester Dual-jet / Vara-jet

TECHNICAL:

Replace your idle mixture screws anytime they are broken, bent, or have visible grooves in them.
Adjusting the Idle Mixture Screws:

The idle mixture screws only affects idle. They simply control the amount of fuel and air mixture that is delivered at idle.
First run the screws in all the way until they seat, lightly. Too hard and you will damage the screw. Now back the screw out until the specified rpm is achieved. Turning the idle mixture screws clockwise (in) leans the idle mixture. Turning the idle mixture screws counter clockwise (out) richens the mixture.
Turn the mixture screws, alternating between the two in 1/4 turn at a time until the engine rpm starts to drop, then turn them back out 1/4 of a turn.
When adjusting your idle mixture screws doesn't seem to change the engine rpm much is an indication that there is something wrong and could be an indication of a needed rebuild.

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APPLICATION:

Rochester Quadrajet Carburetor Idle Mixture Screws 16-139

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