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The Place for Model-A Ford Carburetors

Choke Arm and GAV Driver

Choke Arm and GAV Driver
  • This mechanism allows a single control to provide two functions that interact. It controls both the choke and gas adjusting valve.
  • It is important that the Choke Arm Cam is well engaged into the GAV Driver. Some adjustment to reduce slop can be gained by loosening the two choke plate screws and pushing the choke arm in snuggly, and then retighten the screws.
  • Choke Arm Cams wear and can cause binding of both Choke and GAV movement. A Bent Choke Arm can cause binding. Bent Choke Drivers and Rods can also cause binding.
  • Choke shafts and choke arms must be compatible to insure that nuts neither bind nor provide sloppy fit. Early (28-29) Choke shafts had "steps" that were 0.165" long for the arms that were 5/32" thick. Later (30-31) Choke shafts had "steps" that were 0.13" long for the arms that were 1/8" thick.
  • The nut which holds the choke arm on has 8/36 UNF (SAE) threads.
  • The Choke Plate is attached to the shaft with 2 Oval 5-40 UNF (SAE) thread x 19/64 screws.

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