Rochester 4G Carb

Discussion in 'Wrenchin' Secrets' started by Jonah Halbert, Mar 30, 2018.

  1. Jonah Halbert

    Jonah Halbert Well-Known Member

    My 1966 Buick Electra has a Rochester 4 barrel carb with code 4GC. Does anybody know how I can get my choke working? Also the trans kick down isn't operational. Is there any adjustments I need to make or is there something I need to replace?
  2. Junkman

    Junkman Well-Known Member

    Do yourself a favor and replace that 4GC with a factory Carter AFB . The AFB flows much more than the Rochester 4Jet and you will notice an improvement in performance. The AFB is a bolt on but get one that is off of another '65-'66 nailhead so the kickdown plunger hooks up.
  3. 66electrafied

    66electrafied Just tossing in my nickel's worth

    Agreed; get rid of that 4GC. The AFB is much easier to work with. I've rebuilt carbs for 30 years now and I still can't get a 4GC exactly right.
    Once you have an AFB on it, then you can worry about adjusting the stator rod and the kickdown switch. You'll probably have to anyway considering the 4GC is slightly different from the AFB in throttle alignment. And you need to follow the book when doing it.
    Another option is to try and find a Q-jet manifold and carb; the problem with them was the 66 version wasn't all that good, so you'd have to get a 67 and re-tune it. The manifold and carb isn't cheap either, every now and again someone on the board has one for sale. I have one of each for sale, but shipping to the US is prohibitive from here. (a couple hundred bucks)
    When you pull an AFB off of a wreck, make sure you inspect the base-plate carefully. They tend to rust out if the steel spacer plate was thrown out, which usually it was because it was designed to be sacrificial.
    Jonah Halbert likes this.

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