Is the boat new to you? Or is this a change from previous behaviour?
If the boat is new to you and this is your first fill-up, you may just have a slow-filling tank. This is sometimes caused by a low-point in the fill line
before it reaches the tank, in which case patience will be necessary while filling (and a fuel
-dock that isn't very busy).
Another possibility is that you used the high-volume pump
at the fuel
dock. These are intended for filling motorboats that take on hundreds of gallons of fuel
. They pump
so fast that they generate a lot of foam, and they fill the tank so quickly that that little air vent cannot vent fast enough -- resulting in back pressure and more foam. Try to find a fuel
-dock with a standard-flow pump
Of course, there's also the possibility your fuel gauge is malfunctioning. I would expect that engine to use about 1/3 gallon per hour. So 20 hours of motoring should have used about 7 gallons of fuel. Maybe there's more in there than indicated?