Engine Strange Miss
Balanced carbs..Plugs were toast and the carbs needed attention so well spent.
Here is the original problem. Start out engine runs smooth at 1800-2300 applied power from 2400 to 3400 runs a bit rough but smooths out to 5400. Fly along for approx. 45 to 60 minutes at 5000 and reduce power to 4800 the motor vibrates and feels real concerning. To smooth out I reduce power to 4000 for a brief moment and back to 5200 and will smooth out again for a period of time. This was the original concern before the work I performed and still continues. This is a real gremlin. Is there a rotax guru in Oregon that I could contact for further diagnostics?