I rebuilt a Rochester 2 bbl for my '72 307. The engine won't idle unless the choke is closed. I checked for vacuum leaks and found none. It seems to be the idle circuit (the carb sat for about a year) and no adjustment to the needles affects rpm. Any ideas?

Also there is a check ball (1/8") at the base of the accerator pump cylinder and it is too big to fit in the orifice. Does that matter?

I'd blow compressed air into the idle screw openings after removing the screws. Maybe some crap lodged in there.

Are you sure you matched up the new gaskets to the old ones? Any chance a passage is plugged by an incorrect gasket?

I tried compressed air without success. The gasket idea is a good one, I'll try that next, thanks!