I purchased this Carb on Ebay last fall. Minimal if any previous usage. Been sitting on a Shelf  for awhile. Has the old style Black Bowl and plate Gaskets. Accelerator Diaphragm was flat which I replaced as well as removing the Bowls and blowing out Passages and installing Steel Needle and Seats.and setting Float Levels. I have a 390 CFM  on mine now and it runs great so  I know the Problem is with this Carb and nothing else. It starts but won't stay running without pumping the Gas. It will run at fast speed but dies as soon as the Pedal is released. Won't Idle to set it up at all.I have set the throttle  plates so the transfer slot is just showing so thats not the Problem. I bought this Carb to either install on my Buddies 56 and changing the Distributor or keep it on mine and give Him the 390 which is already setup from being on mine. Any Ideas on what to check before I put mine  back on if I cant get this One to work? Thanks

  

Vacuum leak, incorrect initial idle mixture setting, or the idle circuit is not working.  A way you could check the idle circuit is to spray starting fluid down the carb while the engine is running.  If it continues to run with starting fluid but dies when the supply of starting fluid is stopped, then there is an idle fuel problem.  Have a fire extinguisher handy.  



Lawrenceville, GA

I am thinking there is a problem with the Idle Circuit. Mix screws are 1.5 turns out which should get it at least running at Idle. What should I be looking for as far as a problem with Idle Circuit? I had it partially dis-assembled and blew out Passages with compressed Air and used new style Blue Gaskets.  Suggestions?

  

Take it apart again and make sure the correct gaskets were used.  It's real easy to use the wrong gasket and that can cause all kinds of problems.

RE what to look for regarding the idle circuit.  Assuming vacuum leaks are ruled out, it's not idling because it's either not getting fuel or air.  Make sure the primary throttle blades are actually open and the secondaries are closed.  Do the starting fluid test I outlined previously to rule out idle fuel supply issues.


Lawrenceville, GA

The secondary blades should be open and the idle transfer slot should be showing at least .015" -.020".  Folks get this wrong all the time.  Close the primaries and open up the secondary the correct amount, adjust the idle mixture screws in until it starts to stumble and back out until it cleans up.  Adjust idle rpm with vacuum blocked, and primary set screw after you get the idle down with the secondary blades adjusted.  You can do that be bending the linkage or by the set screw under the secondary linkage if it has one.  Joe-JDC

JDC

Thanks Joe. . I just pulled it back off and put my old one back on the get it running for the Weekend. I just noticed that there are 3 Screws missing that hold the Base to the Body. Holes are threaded in the Body so I I am going to get 3 correct Size Machine screws and fix that. Gonna check the Gaskets that I replaced and make sure they are correct. It will not run at Idle to do any adjustments at all to Mixture etc. I did my 390 CFM Carb so I am familiar with setting the Plates to cover almost all the Transfer Slot.until all U see is a little Square.  

  

GooD suggestions and thoughts from all who have spoken-up on Oldcarmark's carburetor problem.

After the suggestions have been pursued, consider reflecting on some less-often-thought-of possibilities.  Oldcarmark indicates that the carburetor appears to have had little use when he purchased it on eBay.

Just because something is new, doesn't mean it was problem-free when produced, packaged, and purchased.  Occasionally, some of us purchase things longer before we get to use them than we expected.  IF when you go to use the item and there's a problem, you may find yourself unable to return it to the point of purchase or the manufacturer for resolving the problem you've encountered, especially if you have misplaced the receipt.  Sometimes, too, perhaps so much time has passed that the supplier will not honor the return policy or the manufacturer his warranty.

In some previous threads, Ted Eaton has noted problems he's discovered with new out-of-the-box carburetors he's been provided to work with.  My recollection is that Edelbrock produced Carter types have been a problem far more than once.

All kinds of things can pose a problem in the manufacturing or the reconditioning of carburetors.  What I've been told more than once is that the metal dichromating process can result in blockages or restrictions in metered passageways.

Again, there may be a reason why the eBay seller listed that barely used carburetor for sale.  Too, being barely used, the eBay seller himself may be as mystified as we are why it didn't run right when he went to use it.

The above is meant as something to consider when all the good suggested fixes don't resolve the problem.  I've been there myself . . .

Hope this helps.    


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

That's something I thought about this Afternoon as I was taking it off (why was it sold ?). It appears to have never been installed as there are no marks on the Base where the retaining Nuts would be tightened down. Who knows. I will look at a couple of things while I have it off and try it back on again.

  

I’ll suggest checking the base plate to main body gasket for warpage or inadequate / incorrect gasket seal.  Any air leaks at that gasket manifest themselves as an idle problem as the idle circuit must pass through the base plate to main body gasket to get to the engine.  Any air leaks at that gasket simply lean out the mixture.

Lorena, Texas (South of Waco)

This Carb. has the smaller Bores which are 1 7/16 Diameter. The bigger Carbs are 1 11/16 Diameter. Can I use the bigger Base Gasket on mine or is that not going to work? I have a couple of new bigger Diameter Gaskets on hand. Can I use them?