Hmmm... this doesn't look good. I pulled the fuel tank, and checked it out good. The black residue on the tank is a dust, and if the light hits it just right, it sparkles real pretty. I would be willing to bet the pretty sparkle is some kind of metal. It wasn't wet under the fuel hatch cover, just the black dust.

I noticed to that the fuel residue was blacker than normal though, usualy it's that med-dark pink, but it was definatley blacker this time. The engine is practicaly brand new. It can't have more than 15 - 20 flights on it. Oh, and I should point out that the exhaust port on the muffler had rotated on this flight, and was pointing towards the fuse. If you look at the plane/engine from the rear, it was directed at about the 7 or 8 o'clock position - instead of the ideal 4 or 5 o'clock (away from the fuse) position.

I hope it's nothing internal. If anything, I think I was running it a little too rich. I had burned out a glow plug after about 4 or 5 flights after break-in, so I thought that maybe I was running to lean. I turned it richer and have had several flights since.