Holley Carb Problem

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Feb 28, 2006 | 01:49 PM

idealtrucks

Thread Starter

Fleet Mechanic

Joined: Jul 2002

Posts: 1,297

Likes: 34

From: S/W Virginia

Holley Carb Problem

I have an aftermarket Holley 650. I recently put a rebuild kit in it. It runs good, but it has a slow leak in it. After I cut it off and let it sit overnight or something like that, there is gas puddled up on the manifold. It appears to be leaking around the secondary throttle plate shaft. Has anyone else had this problem and how can I stop it?

Mar 2, 2006 | 02:37 AM

lee

Laughing Gas

Joined: Jul 1999

Posts: 1,048

Likes: 22

From: Lacey, WA

Hi,

Ensure that the floats are set to the correct level.

Lee

Mar 2, 2006 | 10:12 AM

idealtrucks

Thread Starter

Fleet Mechanic

Joined: Jul 2002

Posts: 1,297

Likes: 34

From: S/W Virginia

I've got the floats adjusted pretty good I think. The front one I know is adjusted good, butt he back one is adjusted down about as low as it will go, but there is still gas that will run out of the hole on the side of the bowl when you take out the plug

Mar 2, 2006 | 09:19 PM

Ford_Six

Hotshot

Joined: Oct 2002

Posts: 18,488

Likes: 22

From: The Big, Oregon

There is probably something holding the needle open on the rear bowl.

Mar 2, 2006 | 09:34 PM

jade79

Laughing Gas

Joined: Dec 2003

Posts: 900

Likes: 3

When you say you see gas puddled up on the intake, I assume you mean the outside? I'd take it back off and make sure the rear float bowl gasket or fuel line isnt leaking and running down to where it looks like it's coming out of the throttle shaft. If it is coming out of the throttle shaft, I'd still suspect the float. I've seen brass ones develop pin holes and cause it to sink like a boat causinig it to keep the needle valve open. The foam ones can also absorb fuel and do the same.

Mar 4, 2006 | 05:19 PM

LxMan1

Moderator

Joined: Dec 2001

Posts: 22,436

Likes: 17

From: Louisville,Ky.

Remove the needle and seat and look at the sealing point. It may have a small piece of debris in it. Blow it out good and it should be ok. Make sure the the outer o-ring fits snug when you reinstall the assembly in the carb.

Mar 5, 2006 | 12:49 PM

Bdox

Fleet Owner

Joined: Sep 2005

Posts: 28,609

Likes: 18

From: Lake Tahoe, Nevada

One of the above suggestions should fix the problem. I have had a similar problem caused by gasoline percolating in the float bowl after shut-down with the engine hot. This was fixed by adding an isolator block under the carb so that it didn't absorb so much heat from the manifold.