six pack carbs

[HAWS]

It seems like the only carb that is working is the center carb. I can take off the air cleaner, take the car out and stomp it, and there is no power, no deep throaty sound that you hear when all six barrrels kick in.  It is a 71 340, I know something is wrong. Is it a vacum leak? If so How do you check for vacum leaks?? Thanks, harry

[FJ5_440]

First check to see if you can open the secondary carbs manually.  I have seen some cheaper gaskets that could be installed in a way that actually prevented the opening of a carb.  Let us know if they open fully by hand, and we can try to walk you through the rest of the system.  Also some background info on the carbs would be a good idea, such as have they been modified, how old are they, what springs are in them, etc.

[ksierens]

You can also try to apply vacuum to the outboard carbs to see if the the diaphrams are ok.

[Chryco Psycho]

the springs in the diaphragms in the outboard carbs could be too light & opening too quickly causing the bog & the throaty sound

[Super Blue 72]

I'm curious about this...    I wish I had your problem.  I only have a Thermoquad... 

BTW-I think he mentioned there is no throaty sound.... yes? 

Is this set up mechanically or vacuum actuated? 

[ShelbyDogg]

Use a paper clip on the outboard vacuum pod shafts to see how much they open. That will give you some idea of if they open at all and how much they open. I san into a couple of outboards that weren't drilled all the way for a manual linkage. The hole had to be drilled the rest of the way to open up to the ported hole in the bore opening.   With the engine off, open the throttle all the way, then work the vacuum pods up and down. You should hear the air pumping and sucking in the throttle bores.