The fuel tank was essentially full when we purchased the boat. It seems that tank of fuel sat at least two and a half years on the hard and it has been more than a year since the purchase. So, the fuel has sat in the tank about four years. From the supplies left behind, it seems likely the fuel was treated with a stabilizer and a biocide, but we have no idea how clean the tank is. Not wanting to take a chance, we hired someone to polish the fuel. The device that was used recirculates the fuel through a course filter and then a fine one:
The take-up line was attached to a piece of PVC, which was used to “vacuum out” the bottom of the tank:
Then, the fuel was returned to the tank via a second hose that was inserted into the fuel port on the deck.