Help me understand a Carter choke

Discussion in 'Carter' started by BamaWildcat, Feb 28, 2020.

  1. After my carb sat 9 months while the motor was rebuilt it didn't like to warm up as it used to. Had to manually adjust the choke plate to get it to idle- it would die out 30 seconds after running great. Found many issues, one being that my choke pulloff vacuum passage was caked in dirt and carbon. Cleaned it out, and now my choke plate will indeed pop open after crank, like it should except not if I have the choke coil on.

    Please help me wrap my head around what I can do to make this work. If I put the electric choke coil on it seems I'm adding too much physical resistance for that piston to be able to kick the choke plate open a little. I'm also going over in my mind, if the linkage for high idle won't move unless the throttle is open a hair, how would this piston be opening the plate without a foot on the gas?

    Any thoughts are appreciated.
     
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Engine vacuum should be sufficient to open the choke against thermostatic spring tension. That is to prevent the stalling from an overly rich mixture once the engine starts. Maybe that piston is worn/leaking vacuum?
     
  3. telriv

    telriv Founders Club Member

    Send it to me & I will repair it.
     
  4. Tom, I have, and am seriously considering it. I like to think I am handy, but this is trying my patience.

    I've confirmed even with the choke housing off the carb, that the the piston can't act against the force of the electric choke. My carb is missing a baffle plate in the choke. Is that necessary to more focus the vacuum pressure? I've cleaned varnish out of the piston bore and off the piston, and it will work with vacuum without the electric choke. Once the choke is in the mix I see the rod move a little, but it can't work past the spring tension.
     
  5. philbquick

    philbquick Founders Club Member

    Take it apart, clean it and put it back together,
     
  6. telriv

    telriv Founders Club Member

    Maybe you tightened the choke coil too much. Try backing it off to lean a notch or two. I don't need or want any problems after ANY repairs. EVERY carb. I repair for whatever reason gets put on a running driving car. I do a LOT of AFB rebuilding for the whole world.
    I don't need a problem with an overseas carb. It's totally inconvenient for me & you or whoever.
    I also have many/some parts in stock.

    Tom T.
     
  7. I was able to make some progress with the pull off. Right or wrong, I put lithium grease around the piston bore. With that lube helping seal, the piston can now get enough force from the vacuum to overcome the spring. At the beginning of the video, you can see the choke rod moving a little with vacuum. With lithium grease in the bore, you can see it will pull open the choke like it should.
     

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