That's the problem with ethanol, it's so unstable. I don't know how gasoline power boats with big tanks deal with it. Chris, you might consider using small portable tanks in your MC 38 when you're not going long distances. If you've got a few 3 or 6 gallon portable tanks for day sailing it's easy to keep fresh gas and carry it to siphon into your car when the boat doesn't get used as much. 15hp 4 strokes burn less than a gallon/hour.

We used about 35 gallons of diesel this year with our 59 hp diesel. 25 at the first fill up late summer, then 10 more to top it off for winter storage. Tank holds 40. That means our fuel is at least a year old and I never got a complete flush of the fuel system, I didn't run until empty and was diluting old fuel with new fuel each time.