I can only figure the needle was not seated but why would this occur spontaneously? I moved the bike a few feet under cover the night before. No problem where it was or after I moved it. The next morning it started to leak fuel through the float bowl overflow. My wife noticed a couple of spots under the bike when she passed by the bike and a couple hours later I saw a huge puddle and all fuel had run out. I would suspect a damaged float but I've since filled the tank and no leaks.