Again as a new member I come here asking what may be a question that might have been asked many times before. I have a mid 80's Johnson 15hp. runs great no issues there I would like to run fuel that is ethanol free but around here that would mean running a premium fuel (Octane of 91 or higher) I was told its not a good idea to do so. Is that true? 2nd question I have talked to some who recommend a fuel/water separator. I'm guessing this is because of the fuels here that have a 10% ethanol blend. So where in the fuel line does this separator go and is there one brand you would recommend over others?? So there you have it, safe to run premium in a 15hp. outboard, and do I need a fuel/water separator or will the fuel filter handle the job? Thanks again for the honest answer!! 