Back when I was a somewhat usefull citizen I was the lone mechanic for a medium sized fire dept. Had to maintain everything, with many two and four cycle small engines. I mixed the gas mix and renewed it each month. I was always nervous the lads would put straight gas in the saws as we carried both on the trucks. Devised a plan I would mix a little synthetic two cycle oil with the straight gas when they weren't looking used Amsoil at 100/1, if they made a mistake no harm done. The mix did nothing but good for the air cooled four cycle engines too. Frank C.