Just bought a used 25 hp Johnson (1999) Model Number: j25reeb. It quit on me today, i think because it had old gas in the tank?? will this make a outboard quit running? Im now running 89 Octane and a 50:1 ratio, is this ok? it still will not start any suggestions? It was running fine for about 10 min then just quit, got smoky and smelt bad...anything i can do before i take it to the shop?