Adicted:

Usually when a guy gripes about not being able to get a inverted engine to run correctly, need to examine the speaker. Does he always twist on the needle each flight of the day? Are all his engines mounted upright or to the side? Usually this breed of cat is #1, tone deaf, #2 would not recognize a fat or lean condition, or a plug getting ready to die from age? Their engines never, never,never are up to snuff because their learning curve is flat lilne. Idts funny to have a guy cry, get good help and get the engine running correctly, dud flys it one time, very happy with it and then starts to twist the needle the next flight. Go figure!