I just rebuilt a flathead, stuck it in, and it fires up beautifully, only it won't idle. I double checked timing, advance is working, carb has been rebuilt, actually by me after I thought that was the problem but it does the exact same thing.

The idle speed screw is all the way, the mixture screws are one turn out, and when I pull the wiper hose off it idles great, so it seems to be not getting enough air. I rebuilt the carb because I thought that it some dirt or something in it, but it acts the same way. Are the throttle plates supposed to be at least a little open? Mine seem to be shut tight....