I too have had my RC gassers flip and turn turtle still running. No ill effects for me either.

I dont know what to say. Changing your wing and all the build up could be a sign of another problem. Maybe you carb is askew and either too rich? I dont know. Can you post a pic of your piston and cylinder of when you had it open to replace the ring?

Also, give your carb a check, make sure it didnt get knocked loose or bent the bolts such that teh intake manifold block was mashed or warped, and/or the gaskets were springing leaks.

Also, is your pipe still on nice and tight? Again, check the pipe where it bolts on. And look at the pipe itself. If it got a significant dent in it, that could ruin your return pulses to the exhaust port.

Also, check the stinger, makre sure it is not pinched closed or clogged up. If it is only clogged up, that fortunately is a very simple fix.