Ken, I have had good luck with Aviation fuel. It is leaded like gas of old but the valves in the engine like it. I just run the engine dry after each use and before set up for winter remove the plug on the side of the carburetor float bowel to drain it completely dry. Vinny Cell 919-368-2659 S/V Three Sheets 35* 04' N / 76* 58' W h 40 Legend