a vacuum tap will have two pipes on it (for your single cylinder bike), One is the fuel feed to the carb and the other is a vacuum line and this connects somewhere on the carb manifold. As the engine is running there will be a vacuum developed in the manifold, this vacuum is used to open the fuel tap by operating on a diaphragm within the tap, therefore unlike the basic old tap you dont have to switch the tap to Off position when not using the bike. so if your tap has a line to the manifold its a vacuum tap...if it is I cannot say if it can be stripped as I havent done one, but if ther are screws to undo, then why not drain the tank and have a go, be slow and careful there may be a spring or other bits and pieces in there that you wouldnt want to lose!
If you are really frightened of tackling the carb, you could have a word with mervin, he may strip, set the float height and ultrasonic clean your carb for a nominal fee...