63 carb problems

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Dec 30, 2005 | 09:03 AM

T&MRanch

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Intermediate

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From: Roundup Montana

63 carb problems

I'm a first time user of Corvette forum and have a carb problem on my 63 340hp.The carb has been rebuilt several times since 1975 but has always needed to be pumped excessively to get it started. Now it won't start unless you physically pour gas down the carb. It is the original AFB and I need a reccomendation of a good rebuild/restore company. Can anybody help.

Dec 30, 2005 | 10:39 AM

greg57

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bob kunz in st. louis

Dec 30, 2005 | 11:25 AM

JohnZ

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From: Washington Michigan

Quote:

Originally Posted by GREGORY PICCONI

bob kunz in st. louis

(314) 845-2566

Dec 30, 2005 | 12:55 PM

chris ritchie

Melting Slicks

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From: Boston MA

You can rebuild these carbs yourself. It's not a hard job. It is fussy, and it takes time. But it doesn't require any special knowledge or tools. It helps if you have a big table on which to spread out all the parts. The rebuild kits come with pretty good instructions. The ST-12 has a great section on these carbs.

You may have difficulty reaching Kunz. I called him a few times and have now given up. I've heard he's very busy. (Of course, that means he's good.)

Your carb may not need rebuilding. It'll be difficult to start any AFB equipped car after it's sat for about a week. The gas in the bowl evaporates after a few days. When you go to start it, the starter must crank for a while to refill the bowl. Does the car run OK after it starts? Will the car start OK within hours of having run? If yes, then this is what's happening to your carb. It's not fixable. You need to live with it.

Dec 30, 2005 | 04:51 PM

62Jeff

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From: Conroe Texas

Quote:

Originally Posted by T&MRanch

...Now it won't start unless you physically pour gas down the carb...

I have a 62 with a 340 engine and a 3269S AFB. After you get the car running, shut it off and pull the air cleaner. Operate the throttle linkage while looking down the carburator. Does fuel squirt into the primaries? If not, then your accelerator pump is bad.

And yes, even when everything is working right, I have to crank the car for a bit if it has been sitting for a few days, but I don't have to pour gas down the carb.

Jeff

Dec 30, 2005 | 09:02 PM

plaidside

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The Carter carbs use a leather pump pluger cup.
If you can take the top off the carb, soak the cup in some light engine oil for a while. This should soften it up again.

Dec 30, 2005 | 10:16 PM

62Jeff

Tech Contributor

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From: Conroe Texas

Quote:

Originally Posted by plaidside

...soak the cup in some light engine oil for a while. This should soften it up again...

That's a great tip, I think I'll try that tomorrow on the few pumps I removed when they dried out. Still have them laying on the workbench.

Dec 30, 2005 | 10:31 PM

SWCDuke

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If it's been rebuilt in the last 30 years it won't have a "leather" acc. pump diaphragm.

Does the choke close when it's cold?

No choke close, and it probably won't cold start. The AFB choke is subject to getting dirty (Is the manifold heat tube burned through?) and stickly.

The carb and choke system probably just need a PROPER overhaul.

Spend some quality time studying your '63 Corvette Shop Manual AFB section.

See the recent thread on this same subject.

Duke