I do tend to keep the tank pretty
fuel, topping it off about once a month. At this point it will normally take about 5 gallons, which leaves about 15 gallons in the tank.
I will try to keep it at a lower average level - say half full? That would be more than adequate for my needs.
I buy all the
fuel in a 5 gallon container from the gas station I fill my (diesel) car at.
Good point about the O ring...it's probably as old as the boat!