EVERY MOTORCYCLE AND MARINE ENGINE MECHANIC I HAVE EVER TALKED TO HAS STATED IT IS IMPERATIVE TO USE ETHANOL FREE FUEL TO AVOID EXPENSIVE FREQUENT CARB CLEANING/REBUILD. ETHANOL ALSO DETERIORATES THE RUBBER FUEL LINES AND SEALS OVER TIME. I ALSO USE SEAFOAM PERIODICALLY AS A TUNEUP ON 4 STROKE 4...