I just rebuilt my Carter 2100S. I can get it to run but only with the choke. I can't seem to get it to idle at a lower RPM without it dying. All orifices were thoroughly cleaned and blown out with compressed air - idle circuit, accelerator pump circuit etc. I tested the accelerator pump circuit after I assembled it by blowing compressed air into the main discharge with the top off and the pump moved up and down freely.

The rebuild kit contained check balls and a check weight. Does anyone know if the 2100S needs a check weight on top of the check ball in the main discharge circuit? Not sure if that's my problem. On another note, I can put my old Rochester on and it will run so I'm confident that there isn't a vacuum leak elsewhere. A local carburetor shop told me that they rarely see YFs with vacuum leaks at the throttle valve. Not sure if that's accurate but I suppose its open for discussion.

Any assistance is greatly appreciated to point me in the right direction of what to check. Thanks!
Mark

1956 Chevy 3200, 1/2 Ton, 235 CI
https://photos.app.goo.gl/TQQo1YnFjs3U7xB57