Scott......absolutely add fuel stabilizer to your fuel for winter storage!!! And make sure you run the engine long enough to get the treated fuel into your carborator. I feel that bad, (old,) fuel is the number one destroyer of these engines. Also top off your tank so that there is less room for condensation to form which adds water to your fuel. And if it's at all possible and you have never done it, I would pump out your old fuel and fill the tank up with fresh fuel that has the stabilizer added. Then you know for sure that your fuel is not contaminated.