Mystery petrol leak

[mwr09]

Hi all,

My 2002 XT600E has (another) wierd fault. I was riding home recently and stopped at a junction and thought I could smell petrol. Carried on home, and had a look around the bike. Petrol was literally pouring out of the drain hole on the bottom of the carb all over the starter motor, the same with the engine running and when it was stopped. It only stopped when I turned off the fuel taps. The tube which is supposed to be attached to the drain hole had been missing since getting the bike.

I assumed the drain screw had come loose, but looking at it later it seemed as firmly in there as ever. Started the bike and ran it for a while, no leak in evidence. What's going on?

I've replaced the tube to more safely direct any fuel away from the hot engine should it do it again. However, the drain screw is completely rounded off so I can neither tighten nor remove it. Any tips for getting this out?

I've had the carb in pieces a while ago checking its condition. It all seemed fine, and had been running no problem. Please help!