64 Carter carb help

[seok]

I have a fresh rebuild on my 64 Carter carb but it's having some issues, bolted it up and the car fired right up. Vacuum is at about 18" and steady. I'm trying to get it dialed in but The problem is the left idle mixture screw has zero effect on idle. It's running very lean and found that I can fully turn in, or even remove the left screw without a change.  I pulled the carb, opened it up and blew air thru the circuit. Everything SEEMS clear but I'm  more familiar with qjets and haven't worked on a Carter before. What would cause the left side to be like that? What should I look for?

Thanks Matt

[russ austin]

A plugged idle passage.

[seok]

Hey Russ, I pulled the screw and blew air thru it, pulled the primary Venturi cluster out and blew thru every hole I could. Every thing I blew thru felt like it had an exit. Is there a better way to clear the whole circuit?

[russ austin]

The passage was drilled and capped off at the end. You will likely have to remove the cap to get to the problem. You can get new caps on line at the carburetor web sites.

[seok]

Can you show me where that cap would be? I'll look for new ones. Thanks

[dadscad]

When you reinstalled the carburetor, did you put the stainless shim under the carb on top  of the top gasket? Gasket sequence is as follows. bare manifold, gasket, PCV port insulator, gasket, stainless shim. The carburetor will not balance out properly if the SS shim is not installed or in the wrong location. The attached PDF may help with the blocked circuits suggestion that Russ mentioned. The flow circuits are shown to help you understand how fuel flows through the primary and secondary circuits.

[seok]

Thank you for the file. I'll look it over. Yes I put gasket, insulator, gasket, shim. I noticed if I directly spray carb cleaner down the right side primary it stumbles like it should, if I spray it down the left side it loves it. Idle speeds up and wants it. It must not be getting enough fuel from the left primary circuit