No dont drain the fuel , fill it right to the brim this way you wont leave an air gap , besides which I'm sure the Zed doesnt have a drain plug on the fuel system.. Fuel wont go bad in 3 months if you do this
But surely you'll still have air in there? I'll admit I'm no expert on the Z and its fuel system, but surely there's some kind of vent that allows fumes to escape and not build up in there, meaning that the tank isn't fully airtight? Either way, I'd not take the risk.
Maybe drain is the wrong word. Burn it by driving instead!
No you'll always have a small amount of fuel left in the bottom of the tank that will go bad, three months is nothing really, certainly not long enough for a full tank of petrol to go off, I know mines been laid up since October ( in fact since the last Wales run out whenever that was )
+1 Yep Tim is right, fill her up, also stops any chance of condensation building up inside the tank.