F is for Fueltank..

[KnotConnected]

Ran the boat up the river this afternoon for about 4 hours. 1/2 of the trip was idle or just above while we putted through bridges and past marinas, the other 1/2 was a good 10-25 MPH cruise (WOT at times because, why not). Boat ran perfectly the whole time.

Get back to the marina, tie up the boat and I notice the gas cap is missing. ...we haven't fueled up since we were 60 miles north in Menominee Michigan 3 weeks ago. We burned about a half tank coming home from Menominee. Called the fuel dock up there and confirmed they have the gas cap, so she's been sitting with a half tank and an open gas hole since then.

Since then, its rained HARD a handful of times, and its rained softly but all day a few times.

What're the chances that there's water in the gas tank if it ran so well today? If so, how likely is the gas tank to rust now? is there anything I can do about preventing rust if there is water in the tank? Pumping 60 gallons of contaminated fuel would suck, but not nearly as much as sawing the boat in half to fix a gas tank that's rusted through, and I'll never sleep tonight with that thought on my mind. I'm going to check the fuel/water separator and check for water in the fuel filter when I get back up there next weekend to properly assess the situation, but any suggestions or guidance would be greatly appreciated.

 

[Scott Danforth]

Run it dry, then go from there. Add some isopropyl alcohol to have any water get removed during the combustion process. Your tank is most likely aluminum.

 

[JoLin]

What Scott said. Your fill caps are supposed to have tethers on them so you can't drop them in the water or leave them behind. Fix that, too.

My .02

 

[gm280]

If you did get water in the tank, your trip in the boat would have been effected. So seeing how that was a nice problem free boating trip, I wouldn't worry too much about it. The little opening is small enough to not allow that much in. And honestly, you get water in the fuel you buy at any station. They are allowed to sell fuel with a certain amount of water mixed in it from rain run off and leaks in the underground fittings. No gas station is 100% perfectly sealed from such things. And they do test the underground tanks each year to verify it is within acceptable standards. JMHO

 

[Philster]

I'd personally fill the tank with premium fuel and run water separating fuel filters. There are fuel additives that will remove the water, especially small amounts.

 

[airshot]

As long as she is running good you dodged a bullit. Next time there drain the water separator just in case and check any filters. If a small amount did get in there the filter probably caught it. Heck I unscrew my filter a coupe times a year and drain it just to be sure as you can't trust gas stations to be water free.

 

[lineman09]

I wouldn't lose sleep over it .. as mentioned above I don't think u got enough water in there to do any damage or cause problems. run the tank down, refill and put the right amount of fuel dryer in the tank... u should be good togo... PS put the cap back on next time ....

 

[MH Hawker]

been there done that just a few weeks ago, dump in a can of sea foam and go boating it will be fine,