Six months isn't very long for fuel to last, despite what some may claim. Add some Chevron Techron fuel system or fuel injector cleaner, and some top cylinder oil ( Marvel Mystery Oil, for instance) to the gasoline, and top off the tank with fresh gas. I add a cocktail of Sta-bil fuel stabilizer, Chevron Techron, and Marvel Mystery Oil in the recommended amounts to the fuel I store in 5 gallon cans for assorted uses, and it's good for about two years if you start with fresh gas.
