40 gallons? That's a lot of money if you want a refill.
I think that in a sealed container, water free gasoline will last forever. If it's not sealed, daily cycling temperatures from hot day time to cool night time will cause the tank to "breath." I think the effect would be to vent off the aromatic hydrocarbons in the fuel and also breath in water vapor in the air. Since gasoline today has alcohol in it, the water can dissolve in the gasoline. I worry about the water situation, since I don't drive my 68 much, I worry about rust forming in the tank or corrosion in the carburetor which is made out of pot metal. Also, I do know that if you get a layer of actual water on the bottom of the tank, a reddish brown anaerobic bacteria can start to grow in the interface between the gasoline and the water. This stuff can clog up fuel filters. Also, just plain old tank rust and rust forming in the steel fuel lines is a potential filter clogger.
In your situation, for me, I'd worry about rust forming in the fuel tank and clogging up a fuel filter. If there's any rust in the system, the rocking of the boat will kick up the rust. Anyway to stir or agitate the fuel to see if it turns to a reddish brown color?
For old gas that's lost it's aromatic content, I'd think buying a can or two of Torco, would do the trick. The guy that dyno tuned my 08 (Andy Green of A&A Vettes), says it's the only fuel additive he's found that actually works. Best I can tell Torco is really just heptane and octane, so these are the aromatics you want back into the fuel. His story was that on an ~700 rear wheel hp car, Torco allowed him to dial up advance to get another 70 Hp.
..........................
About bacteria fuel for disbelievers. Just months after WWII ended, military aircraft in Japan, Philappines, etc. began having problems with fuel filter clogging. The AF equipped a B29 with lab equipment and my father, a chemical engineer, was one of the civilians sent on the trip. The plane flew from Wright Patterson AFB to Hawaii, Philippines, Japan, etc. My dad's seating assignment was in the tail gunners position. By the time they got to the Philappines, they knew what the problem was. They kept it a secret since they wanted a boondoggle trip to Japan. It was the trip of a lifetime!
With the end of combat operations, the AF decided to drop the octane rating of av gas to save money. The drop in octane, and particularly the tropical warmth of places like the Phillapines allowed anaerobic bacteria to start growing if there was any water present in the gasoline. The recommended solution was simply to increase the octane specification level to war time levels.
Returning from a trip to Mexico in the late 60's, by Mustang fuel filter clogged. The fuel was reddish brown. I think they had to drop the tank to flush it. Who knows what it was..just plain water generated filling station tank rust or maybe those infamous bacteria.
prrtt: MOST/some of you know the story....enough....:gurney:
