I'm sure this question has come up before, but here is my dilemma: I still have about 70-80 gallons left in a 105 gal tank (ocean boat) from last June. I put in fuel stabilizer in the tank back then and had the boat stored. Never had a water-fuel separator filter before, but putting in a racor right now along with a new fuel-injected volvo penta inboard. Should I siphon the old fuel out or keep it and get another additive? Thanks for your advice.