Hello All,
I know this is very basic, but I have a few simple Six-Pack questions ...

When you start up the motor - is it just the center 2-bbl that initially is in use? And is it just this center carb that needs a choke to be present/working?

If you adjust idle - do you just adjust the center carb? Or do the outer carbs get fuel at idle as well?

If either or both of the outboard carbs were to flood, what would happen to the motor? Would it die or keep running on the remaining carbs?

Thanks much for any insight into this. I searched around the web and couldn't find any basic intro on six-pack carb operation. But if anyone knows of one I would be grateful to hear about it!

Thanks much!

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When you start up the motor - is it just the center 2-bbl that initially is in use? And is it just this center carb that needs a choke to be present/working?

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Yes & Yes

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If you adjust idle - do you just adjust the center carb?

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Yes

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If either or both of the outboard carbs were to flood, what would happen to the motor? Would it die or keep running on the remaining carbs?

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Depends on what you mean by "flood" if you mean start burping fuel you've likely got a stick needle & seat or your bowl levels are set wrong, in either case the engine should be shut off until the problem is corrected weather it continues to run or not, otherwise you'll be inviting a carb fire.

*BTW, that was at least 4 questions

When you start it up, the center carb is the primary device for choke function and basic idle speed However, the end carbs Do have idle circuits that are fuctioning as soon as the engine is running. The center carb is the only one with a choke.
When you adjust idle, the center carb controls idle speed, But all the carbs have idle circuits that must be adjusted initially. Once they are all set up correctly, the center becomes the carb normally adjusted for minor issues. The idle speed is only on the center carb, although there are some tricks available to adjust the ends, but it is not really necessary.
If any of the three carbs flood, it will die just like any other carb setup. Hope this helps, Lee.

Thank you both for the answers!

In this case, I want to help a buddy adjust his idle -- it's a bit low, but otherwise the car runs Ok. So, it sounds like I just need to tweak the idle setting on the center carb 'til it's a little higher.

If all 3 carbs are getting fuel at low rpm, for example - idling at a stop light, when are the vacuum secondary attachments on the carb used? I've heard where people say when you really hit the gas hard on a six-pack, the "outer carbs kick in". What would this mean? Are they not being used at lower or cruising RPMs?

Thanks a lot for your help .. this is a completely new concept for me!

The end carbs have idle circuits for a reason, it was to keep the fuel from going stale in the bowls when they were not in use, as if the end carbs would go for very long without getting opened up!!
The end carbs operate off a vacumn source that originates in the venturi of the center carb, when it is wide open or has high air flow, it creates a vacumn signal that goes to the pods on the outboard carbs and opens them up. The end carbs have a tiny kill bleed that bleeds off some of the vacuum to keep the ends from opening until the engine can handle the additional flow.
In short, the end carbs do not open under normal driving/idleing conditions. Under idle conditions, they do contribute to the rich/lean condition of the idle system. This is kind of a simple explanation, but basically covers it. Lee

While they were sealed from the factory, it does not mean they are perfect. They were sealed for emissions purposes. The majority of the six-packs I work on do not have a stock cam, even going up to a mild grind like the comp 270 requires rebalancing the idle circuit for best driveability and idle.

lotsa "idle tricks" one can do with the 6-bbl setup.

Thanks all for your replies!

Would it be true to say that for basic troubleshooting of starting or stalling at a stoplight, the main focus would be on the center carb? I haven't yet experienced either of these issues with the six-pack setup, but want to gauge where my immediate focus ought to be in case that happens.

Also, anyone know of a site or book which does a good job describing six-pack carb setup or troubleshooting for someone new to all this?

Thanks again for your help!

Here's a link to some good reading... .. 6bbl tips