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    Results 1 to 10 of 10
    1. #1
      Join Date
      Aug 2007
      Posts
      271

      Aggravating Holley Leak!

      A recent rebuild of the Holley 750 db for the wife's 68 Camaro SS has me frustrated to the point that I'm likely to order a new one from Jeg's today and be done. Motor is a sbc with a thumpin' cam, Brodix aluminum angle plug heads and incredible torque. The problem is after the rebuild, the mixture screws in the primary metering block are leaking! I have never seen anything like this in all the years I've worked on cars. Bought a set of the cork seals from Holley, installed (correctly), fire it up and although the engine is running great with excellent throttle response, begins to dribble out of the bleeder screw area (WTH). I have done this 4 times with same results!
      As a last ditch effort I decided to ask for help as the local speed shop provided no solutions. So here I am guys, what can I do to resolve this issue or am I just going to call Jeg's for another 750 dp or possibly a 770 Street Avenger!

      Tom Koontz


    2. #2
      Join Date
      Mar 2011
      Location
      Ca
      Posts
      336
      Country Flag: United States
      sounds like a metering block tolerance issue, did you happen to try the rubber gaskets yet, they may seal better than the cork.

    3. #3
      Join Date
      Aug 2007
      Posts
      271
      Only been able to find the cork one's. Even Holley's website lists them as only option. Seems like a poor choice for sealing fuel!
      Tom Koontz

    4. #4
      Join Date
      Nov 2006
      Location
      NH
      Posts
      269
      Country Flag: United States
      Tom,
      Did they sand blast the carb?
      Jeff
      SHAKER TUNED SOLUTIONS

    5. #5
      Join Date
      Nov 2011
      Location
      Virginia
      Posts
      229
      Country Flag: United States

      Aggravating Holley Leak!

      Sounds like your throttle plates are open too far, removing vacuum from the idle circuit. You'll know this is the case if you can close both idle screws and the car still runs.

      Nothing should drip from the idle mixture screws; they are supposed to be exposed to engine vacuum - something to check.

      http://i1207.photobucket.com/albums/bb476/waynep712/waynep712%20carb%20album/holley_atIDLE_zpsbdbaea76.jpg

    6. #6
      Join Date
      Nov 2011
      Location
      Virginia
      Posts
      229
      Country Flag: United States

      Aggravating Holley Leak!

      Not my pics by the way... Credit to the guy why posted them. I just found them via google to try and offer assistance.

    7. #7
      Join Date
      Mar 2011
      Location
      Ca
      Posts
      336
      Country Flag: United States
      Tom the rubber gaskets may have been from a Barry Grant kit. checking your throttle plates might give you an idea whats going, i've never had a carb leak out of the adjuster screws before. if it were my carb i'd remove it from the engine and start tearing it down and check all the internal gaskets to make sure a wrong gasket didn't get installed by mistake. i'd also look for cracks in the main body and metering blocks just to be safe.

    8. #8
      Join Date
      Sep 2006
      Location
      Southern Indiana
      Posts
      4,709
      Country Flag: United States
      Does it have 2 metering blocks? Get front and back swapped?
      Somethings is odd. Most good Oreilly has metering block gaskets, I havent seen much cork on any holley for years, butthen most I have seen have been newer ones people have all messed up and I just have to get back in adjustment. Only way fuel would drip from idle mixture screw would be if it saw fuel pressure as all I have see the mixture screw seals for was to keep needle from moving not sealing in or out much more than dirt.
      Lee Abel
      AFTERMARKET PERFORMANCE

      1977 Chevy Monza 2+2:Project "Cheap Trick"
      1978 C10 Long bed , On air and trailer puller
      2006 Buell Blast ,Just a bike to ride and for mileage
      1966 Caprice 4dr Sports Roof fact.327/now 350/SOON 454???? Project "II Old,,,ZERO BUDGET OR LESS CAPRICE!"

    9. #9
      Join Date
      Sep 2006
      Location
      Southern Indiana
      Posts
      4,709
      Country Flag: United States
      Now if your taling sight adjustment hole that means floats are too high/stuck. maybe few quick pictures pointing too affected areas.
      Lee Abel
      AFTERMARKET PERFORMANCE

      1977 Chevy Monza 2+2:Project "Cheap Trick"
      1978 C10 Long bed , On air and trailer puller
      2006 Buell Blast ,Just a bike to ride and for mileage
      1966 Caprice 4dr Sports Roof fact.327/now 350/SOON 454???? Project "II Old,,,ZERO BUDGET OR LESS CAPRICE!"

    10. #10
      Join Date
      Aug 2007
      Posts
      271
      I'm going to tear it down this weekend and see if something is a miss.
      Tom Koontz




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