I wouldn't recommend this, not only are you letting your bike sit there idling for no reason with no cooling, you're running it lean because of the fuel starvation, and the carby won't be empty once you're done either.to get the fuel out of the lines when you finish before you turn off the bike just turn the fuel switch off and and wait till the fuel runs out of the lines and then it will shut itself off
If you wanna drain the carby open the drain screw at the bottom.