Mine's growing a varnish stain on the exhaust header, but that's it.

Mine does show some carbon in the combustion chamber, but not lots.

One thing I meant to say, after as much fuel as you've run thru your engine, there's no need to run it especially rich. 300-500 rpm below peak is great, any richer and you're throwing away fuel, power and engine life.

The comments you're getting on the possible liner peeling are a result of a problem OS experienced a few years ago when they switched from chrome liners to nickel plated liners. Some early ones had longevity issues, and modlers have long memories. It's no longer a common problem.

J