[Bill Cuthbertso]

Gary,
When I turn a carb upside down and operate the butterflies, it appears that once the butterflies leave their seat all of the transition ports are exposed. Give it a try. It seems to me that in order for the ports to be exposed one at a time the carb would have to equipped with a slider of some sort instead of butterflies.
Plugged holes - pull the plugs and tap the holes.