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old 72 style roch Q jet power piston spring ?

Discussion in 'The Garage' started by R72K5, May 23, 2005.

  1. R72K5

    R72K5 Banned

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    is there supposed to be a spring standing up under the power piston assembly on the 1972 chevy Q jets or did not all of them get a spring ?

    7042206 is the carb stamping


    thanks
     
  2. R72K5

    R72K5 Banned

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    well i looked at a diagram and saw one so i dug through my Q jet parts stash and found one of the springs and put it under the PP asembly and the damn new accelerator pump was not squirting so i robbed an old beater one from a 78 Q jet and its good to go squirts and runs top notch excellent now

    yay!
    the PP assembly in the 72 and 78 carb are the short body style BTW, dont have the threaded in brass deal with stem with two flat sides on it in there

    something called EPT setting or something that the later oens have ? i forget what its called, the older 708 and older series Qjets dont have this thing apparently



    thanks
     
  3. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    Its an APT on later carbs , adjustable part throttle . Its basically your primaries fuel mixture control .

    On my basically stock 305 with one of those , 1 turn out passes emissions , 2 3/4 turns out is best balance of power and mileage , and 4 turns it runs rich but like a scalded cat :D

    Edelbrocks with one come 2 turns out from factory I believe .
     
  4. R72K5

    R72K5 Banned

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    good info pauly, appreciated :D

    APt is what i was trying ot remembe,r yep!

    lol

    :thumb:
     

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