"To set basic idle speed for a firs start up after rebuild I flip the carb over and open the speed screw as much as I can with out uncovering much of the transfer slot, mabey .050 of it.

This will almost always get them idleing where you can adjust them"

OK you lost me. I'm not sure what you are referring to. I have a 71 carb and I don't recall seeing any screw that would affect the transfer slot?