3 hp tiller?

wont run at higher rpms.
I cleaned all the gas and running with the air cleaner off I spray slowly air into the carb and she runs fine. The fuel white tube is clear but the other small gas tube looks like it has a small ball that doesnt move. theres a roll pin and capped off with a small metal peice. its rusty from the bad gas but looks like a fuel dump over that may not be working properly which send all gas to engine without control of some kind. Could that be my problem?

Terry
April 2010