Yeah, I have the same problem on my cub. I get noticeably more smoke out the right pipe, and that pipe is actually cooler than the left. When I check the plugs the right side is wet with no noticeable smoke ring, while the left pipe is hotter and dry with a perfect smoke ring. The motor was just rebuilt with the cubby, so the crank seal is not an issue and the compression is fine at 185. The thing that I was leaning towards was the coil. I think the right plug wire is not as good a spark or as consistant which would explain the unburnt fuel (blue smoke) and the wet plug on one side. Plus would not show a smoke ring if it wasn't burning the fuel completely.............
Just my .02 :biggrin: