Carb intended to have vacuum leak??

**USMC4LIFE** · 06-15-2012, 07:06 PM

Bought a rebuilt Rochester 2bbl for a 62 Buick LeSabre with 401. When I put the carb on to dial it in, I noticed that the engine went from 21 inch of vacuum down to 16 inches of vacuum. I sprayed around the carb to find any vacuum leaks. I found that when the gentlemen rebuilt it, he put what appears to be the wrong gasket in-between the base of the carb and the carb housing. When i asked him about it, he told me that was there to help atomize the fuel to assist in better fuel economy. Has anyone ever seen or heard of this before. I opened the butterflies and shined a flashlight in there. You can easily see the light coming out through gasket at the bottom of the carb. Pictures of the carb are attached. Also attached is a picture of the rebuild kit. The arrow points to the current gasket being used and the circle is the one that i think it requires. Any help would be really great.

**raycow** · 06-16-2012, 01:42 AM

I think you would definitely want to get rid of those air leaks visible in the picture. However, the correct gasket could also be the one to the left of the circle. It all depends on what you find when you take the carb apart. Specifically, is there a passage in that protrusion between the two throttle bores?

Ray

**carmantx** · 06-16-2012, 06:02 AM

Correct, you should not have a gap in the base gasket. It should seal tight to the body and have NO vacuum leaks.

**USMC4LIFE** · 06-16-2012, 08:55 AM

Thats what i thought. I replaced that gasket today. Back to 21 inches of vacuum and runs like a new car. Thanks for the response.

**raycow** · 06-16-2012, 10:37 AM

Which gasket (in the picture) did you end up using?

Ray

**USMC4LIFE** · 06-16-2012, 01:55 PM

I used that gasket that was circled. From what I have been told by some hard core old timers, the one he had in there is for the dumpers on a 3x2 set up. Runs great now. Finally after 11 years, I got to drive the old car today!!! Man did it put a smile on my face.