[durand322]

I've Got a used rebuilt holley 4150 double pumper 650 cfm. My dang truck ain't wanting to run right and i'm having a very strong gas smell from the exhaust. I was recently told that the fuel level could be to high and that this carb is not set up for a HEI distributor. The engine runs fine for the most part when it's in park/neutral when idling. When the engine either shuts of or dies on me, there is a fog in the carb and I'm thinking that the carb is spittin in too much gas. When I stick it in drive I have to keep my foot on both the gas and the brake to keep it from dying on me. Can anyone help me?????

[BOBCRMAN@aol.com]

If it is a "Double pumper" as opposed to a dual feed. Then you have entirely WRONG carb for a stock type motor.

If it is continually rich it can be High fuel level, stuck float, jetted way to rich or blown/wrong power valve.

[durand322]

Originally Posted by BOBCRMAN@aol.com

If it is a "Double pumper" as opposed to a dual feed. Then you have entirely WRONG carb for a stock type motor.

If it is continually rich it can be High fuel level, stuck float, jetted way to rich or blown/wrong power valve.

Then would a Rochester Q-Jet work better?

[cobalt327]

Originally Posted by durand322

Then would a Rochester Q-Jet work better?

I would say yes.

Using an adapter to put a Q-jet on a square bore intake sucks, but will probably be better than a DP that needs work. Hopefully, you have a spread bore intake w/an adapter to mount the Holley.

The 4777 is a good carb, don't get me wrong. One of my personal favorites, in fact. But there is a place for it, and your truck really isn't it, unless you can tune it properly to work w/the combination of parts you have.

If you want to try adjusting the 650, start w/checking the float level.

Good luck.

[a1supersport]

Originally Posted by durand322

a used rebuilt....

Depending on how-used, and who rebuilt it...that could be your problem. Never take a person's word for it. Doesn't matter if they've been rebuilt 39263827648 carbs, for 1829372-years...always go through it so you know what's in it. If you rebuilt it, you should have no problem going back in to see what's wrong.

P.S. There's a couple other threads in here that sound just like yours...