Results 1 to 3 of 3

Thread: Here is a tricky one.

  1. #1
    adder Guest

    Default Here is a tricky one.

    Hi all,

    Here's the deal.

    I have a 4781 that leaks under the front of the carb. If I run my fingers across the carb to manifold gasket, I get a stripe of gas across my fingertips. Not bad. When the car is hot it evaporates and it is dry. After the car cools, it is wet there for a day or two. (it is not he bowl, power valve or metering block gasket.)

    I do have gas washing down. Plugs are wet and after time (2 months) I notice gas in the oil.

    I have swapped out the bowl and metering block. No change. I have put in new gaskets, power vales, needle and seats, accelerator pumps, etc. The float levels and pump adjustments are correct.No change. I put my metering blocks and bowls on a parts main body I have (although it ran like crap) it was dry as a bone.

    I am assuming I have a cracked main body or the base-plate to body gasket is bad. It is weeping inside the carb, soaking the front of the intake manifold gasket and washing down the cylinders. I can't put my finger deep enough down the throat of the carb to feel where it's wet.

    I really like this carb. Even with this problem it performs great. It idles nice and it is very responsive. It doesn't lag, pop, stumble or anything. I can stab the gas peddle or run the rpms up slow. It runs flawlwssly. I do not want to get rid of it.

    This problem is only in the front of the carb.

    How can I check for a crack or a bad gasket in the main body?


  2. #2
    Join Date
    Dec 2009


    Have you tried replacing the main body gasket (throttle body gasket)?
    If you don't need a choke, you can buy Holley's main body replacement and attach all your hardware on it:
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

  3. #3
    adder Guest


    Thanks, that is what I will try next. No I do not run the choke on it.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us