Thanks both daman and stillcrazy for the quick replies. In all the time I've spent thinking about where this leak is coming from, I probably could have pulled the carbs and fixed it by now. The bowl itself is wet on all sides, and is also wet slightly above the mating surface of the bowl / carb body. Even when standing still overnight and I wipe the carb down, the bowl is wet (along with a few drips below) the next morning. As daman hinted, its hard to believe that the pilot screw would be leaking. I'd be more inclined to think that the O-ring between the bowl / body is leaking. My only other thought is that the bowl drain is leaking as stillcrazy mentioned, and the fuel wicks up the sides of the carb bowl. Guess I should just bite the bullet and remove the carbs to see what is going on. I've never had them off before, and it looks a little ugly getting the airbox wiring, etc out of the way to remove the carbs.
