Blk63Vette

Hello

I been trying to dial in my Corvette. I'm running into issues. I have and original 1963 Carter carburetor 3461S.

The problem

Vacuum at the port at Idle appears to be cross leaking internally into the carb. Show vacuum gauge is showing (20) at idle.

The mechanic think its a base (carb) problem. I'm not sure what to think. Rebuilt the carb it did the same thing.

Any suggestions? This is all over my head :/

thanks
Pete

JohnZ

Don't understand the issue - what are the symptoms, and how did it start? You didn't say which engine you have (that carb was used on both 300 and 340hp engines), and 20" Hg. at idle isn't out of the question on a 300hp.

Blk63Vette

Hi John

Thanks for the response. I'm not a carb guy. So my I am unfamiliar with them. The mechanic is very knowledgeable but, like he said wasn't very familiar with this carburetor. He was trying to set the timing and was having issues with "in his words" the large amount of vacuum from the front port. was making it difficult to adjust the timing correctly. He though there was too much vaccum. Thought shouldn't be as much. I am unfimilar But, before I "ching $$$" more money out on a new carb I'm not 100% sure its a carb problem.

I'm thinking its not a carb problem maybe a lack of knowledge thing.

Pete

tbarb

Pete,

There is nothing wrong with your carburetor. The port in the front of the carburetor connects full manifold vacuum to the distributor vacuum advance can.

Set the ignition timing with the rubber line unhooked from the distributor V/A control plugged with a golf tee. Get the idle speed down to approx 600RPM and set the timing to 8*BTDC.

JohnZ

He's probably not old enough to remember cars with carburetors with full manifold vacuum ports; he's probably only seen emission-controlled cars with "ported" vacuum, and that's why he thinks it has "too much vacuum".

Blk63Vette

Thanks

John Z

I think I'm going to have to looked at and rebuilt. I found a needle screw on intake (oh god help me) I want it rebult by a professional (for a piece of mine) Does anyone have suggestions??

Thanks
Pete

63redvette

Boyan

Put the idle mixture screw back in and set both screws 1 1/2 turns out from bottom and see how it runs. What engine do you have and is it stock?
Boyan

Blk63Vette

327 300 hp 4 spd car stock 3461S carb

thanks
Pete

tbarb

I would send it to Bob Kunz, you will need to search for his phone #.

His son is doing the work now and someone posted that Sr. passed but I am not sure.

Whatever you do keep in mind that 3461S carburetor is a one year only part # and very $$$ to replace so don't give it up to just anyone. Why do you think it needs to be overhauled.

rfn026

I had a really good experience with Quality Craft South in Fort Myers. He's not that far from you. 239.337.0615

Richard Newton
Car Tech Stuff

Blk63Vette

Hello Story why I want carb rebuilt professionally

I had the carb rebuilt years ago. I did notice that there was a pieces MISSING from the last rebuild. This recent rebuild was done by this guy who cant dial in this carb and get the car running right. He replace the SS gasket with a bigger one and the accelerator rod was pinched inside the air cleaner did a extremely high rev after that I (limping it home).. This mechanic worked in two corvette shops in Sarasota!!! I'm ready to bring it to Orlando I need the top replaced maybe have Mike Coletta fix the top and get Mark to fix and dial in the Corvette.

Listen I'm tired of paying for mechanic "s" not able to fix my car. Not just taking my car to "any" mechanic these are "Corvette" mechanics.. Christ Sake I'm at my witts end.

tbarb

I feel your pain, just take it one thing at a time. Post a picture of the set up, I would like to see what's missing.