Have never used a air filter as I am told that there is loss in performance. Recently I saw a specific review wherein the reviewer used a piece of cotton stocking in top of the carb inlet held in place with a wire tie. Does that help and are there any more suggestions? I dont mind spending a bit if it improved engine life. As for the points that ArcticCatRider raised, checked all of that except pinching lines with engine running as the engine (75AX) was cowled

Ameya