The intake system on Club Cars HAVE to be
intact for it to run correctly!
Air filter, air box lid, intake tube all need to be connected and sealed!
I've heard of instances where the air box lid wasn't clipped properly, a bad carb gasket, or the intake tube had a crack in it.
Hook everything up, run it part throttle in maintenance mode, spray carb cleaner all over the air box, air tube, and carb...
When you find the air leak, there will be a noticeable RPM change!