I recently purchased a new outboard. Its small, but perfect for my boat. 9.8 hp outboard and it hardly uses gas at all. It came with a 3 gallon tank and I have taken it out twice now... had to have put 3 hours on it by now and the tank still has at least 2 gallons in it. I filled the tank up probably 3 weeks ago and I really haven't had the time to get out on the water except the weekends. How long does it take for gas to spoil, should I put some fuel stabilizer in the tank? The last thing I want to do is gum up the carb. on a brand new outboard.