the best way to drain the tank is to undo the fuel tap and pull it out,they work on a vaccum so it would be hard to drain any other way unless you want to suck on the vaccum hose for ages ?just undo the tap clamp on the bottom of the tank and the tap will pull straight down and the tank will drop all its fuel.follow bb's advice on the carb side of it.
adam bike doctor, July 2010