I gave up on the red Sta-Bil years ago, it just doesn't do anything with E10 ethanol gasoline and it does have a short shelf life once the container is opened. The blue Sta-Bil does work but is pricey. I've been using a mixture of Star Tron, Sea Foam, and ValvTect Carbon Free when I refill my 5 gallon gas jugs with 89 or 91. Then for my two strokes all I do is add the oil when I refill their smaller jugs from the 5 gallon jugs. None of these additives are inexpensive and significantly increases operating costs, but you gotta do what you gotta do to keep the equipment running. Stihl power equipment carbs seem to be more sensitive to E10 gasoline than other makes with the same Zama carbs, I don't know why!!!
Mad Mackie in CT:biggrin::smile::laughing: