Hopefully your "on/off" petcock still works ok. If not just get an aftermarket on/off switch on eBay there are tons of them. When you are done with the bike just shut the petcock down and run it a minute or two to empty the carb bowl. If I don't do this on my dirt bikes these days the fuel goes bad quickly enough to make me drain the bowl in about 3-4 weeks if one sits that long. The problem is the dirt bikes tanks (and vintage bike tanks) aren't sealed tight like newer streetbikes and cars are. I would just use a fuel treatment like Lucas Oil brand (called safeguard ethanol fuel conditioner - a cap full per tank) and cut the fuel on your last minute of riding home. Then when I want to fire up a bike or lawn mower etc.
I just turn the fuel on, add some fuel and away I go. That's how I have to do things around here in CA.