Holley Electric Choke Question

Fuel and Air Systems

  1. mopowers

    mopowers Well-Known Member

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    How important is the vacuum signal for the electric choke on a Holley carb? I've noticed Proform and other Holley-type carbs do not have a connection to vacuum.

    Is it to cool the bimetal coil in the choke housing?
     
  2. mopowers

    mopowers Well-Known Member

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    Also, does anyone know what this piston does (circled below)?

    choke.jpg
     
  3. toolmanmike

    toolmanmike FABO Staff Staff Member FABO Gold Member

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    Primary pull off? Just guessing.
     
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    • krazykuda

      krazykuda FABO Gold Member FABO Gold Member

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      That piston moves up and down...
       
    • diymirage

      diymirage HP@idle > hondaHP@redline

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      not necessarily, you can clock it so it moves sideways
       
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      • mopowers

        mopowers Well-Known Member

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        Actually, you can't. It's part of the housing that's affixed to the carburetor.

        I believe the piston meters the vacuum signal. When the engine is cold, the piston is up, not allowing vacuum to flow. When the thermostatic choke coil heats up, the piston moves down allowing vacuum and subsequent air movement to help cool the coil and keep it from overheating. That is my theory anyway.

        Does anyone know for sure?

        My question still remains though- How important is the air flow from that vacuum source if some electric choke housings have it, and some don't?
         
      • diymirage

        diymirage HP@idle > hondaHP@redline

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        just clock the carb, junior

        clock.gif
         
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