It may not be like glow fuel residue, but it is a significant amount of a gummy, black coating of goo that is not as easy to wipe off as glow residue. "Goo" is the best way to describe it. I have about 24 flights (~3 ½ hrs) on it so far, and the black residue has decreased a lot, but there is still a fair amount of it all over the airplane after a day of flying. I’m not complaining about it, but this engine in NOT like a typical gasser that only puts out small specks of black stuff. All-in-all, I absolutely love this power plant! After a couple of gallons, I may decide to reduce the oil ratio to 25:1 and see what that does. Yeah, I know, I know...voiding the warranty, replacing parts, etc. but I’ll save that discussion for another day. Besides, Pete did say there were still experimenting with oil ratios.

Dave