View Full Version : Holley 4150 carb help needed!

07-04-2015, 03:28 PM
I've a seeming ongoing problem w/the TR carb. The engine is a 509 CI GM type Big Block.
The problem is, while closed (idling), the secondaries dribble fuel from around the mounting
points of the boost venturis and it puddles on the secondary butterflies. The carb is a marine
Holley 4150 800 CFM, list #R9022.
I've carefully set the secondary float level w/the pump running at 4 PSI, but the engine NOT
running. As soon as I start the engine, it starts dribbling fuel again.
I've carefully read the literature on the Holley site, and I also have an HP Books Holley manual,
but I can't seem to find a solution.

Here's lots of pictures, and if anyone has ideas, it would be appreciated:









07-05-2015, 09:17 AM

Does Holley have some tech support? If so, did you call them and what did they say?


Barry Eller
07-06-2015, 07:59 AM
Jim Haas may know. Possibly a vacuum issue.

07-06-2015, 11:22 AM
I'd put a new needle and seat in it before considering anything else. I used to have a similar issue with my drag car after it sat for a while. I think I eventually put in the steel Holley needle set for alcohol fuels and it went away for good. Fuel will dribble out the boosters when the needle and seat leaks or the float level is too high.

07-08-2015, 09:17 AM
I hate carb issues my holley is almost out the door for something new

07-21-2015, 08:56 PM
If the fuel is coming from where the booster Venturi is mounted to the carb body, it sounds like it or they may not have been fully seated when they were "peened" to the body. The venture has a "sleeve", much like a rivet, that sticks through the carb body, and is "peened" to set it. This also seals it to the body to prevent the type of leak you are describing. Holly should take care of it, I would contact them.

07-22-2015, 09:40 AM
Thanks for the info.
I took some time to carefully blow through all the porting on the secondary
side and it seems to have fixed the problem.
Even all the soot is staying off the transom after cleaning.