Today's ethanol gas does not last long. I add the blue marine StaBil to every can of gas, and then I double the dosage before I do the last run on the engine before the winter. Helps a lot. But, another problem is that the 4-stroke outboards many are using have tiny jets in there, which is one of the reasons they sip fuel. The low speed jet is really weensy, and the teensiest bit of crud will plug it up making your engine hard to start and run. You might be able to get around this if you disable the gizmo that prevents using full throttle at start up, and then give it a few cranks with the throttle wide open. Sometimes that works, but then you have the problem that when you throttle down the engine dies. You really need to add a big spin-on type of fuel filter if you plan on getting any kind of use from a 4-stroke outboard, even a dinghy motor. Even then, keep onboard all the tools you will need to break down the carb and clean out the low-speed jet. I got so I could do it in ten minutes on my old 4-stroke Yammy. My current dinghy motor is one of the last 2-stroke Johnson 6 HPs, which has been totally reliable for about seven years, and 5 of those 7 it got daily use.