You are the one who did it, not me. 1/4 ID is bigger than I thought. Good job. Glad to offer encouragement. The guys before me had the ticket already. (Dave, Carl, Cuda). Carb just needs tweaked and maybe a rebuild. Now get some electric wipers for all that rain I wish we had.
Since the idle mixture screw does not actually control mixture, but controls volume, you had too much volume to be atomized. It needed more air flow with the throttle closed. So it got it from the open hose. You slowed down the volume of air/fuel into manifold and it does not need the "extra" air. Just what air the throttle plate lets past and/or idle bypass circuit provides. I think I would call it that it was running "rich". I guess it was flooding out. Not sure about all this. I made it all up.
