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Draining some gas?
Posted: November 19th, 2022, 4:52 pm
by tonyiiiafl
My 390 is on teh hard, and since it has been warm and the high angle the bow is in, some gas was leaking out of the vent on starboard side. I loosened the fill cap and all stopped leaking, however, yard asked me to drain 10 or so gallons out. Sounds easy! HOWEVER, when i tried to put a 5/8” ninny l hose down the fill pipe it went in about 3’ or so and stopped. I moved it around, twisted it, etc, but it made a sound like it had bottomed out in teh tank, however, the end was not wet. So i figured there may be a screeb(?) at the tank inlet? I went to HD and got a 3/8” poly ice make line, as it is stiffer, and again, teh same thing happened. I turned and twisted, but after 10 minutes I gave up.
Does anyone know if there is a screen/grate at the filler neck on top of the tank? All I can think of ..
Thanks !
Re: Draining some gas?
Posted: November 20th, 2022, 9:59 am
by Cooler
Yes there is a back flow valve in there, as required by regulations. In case a boat would sink, the fuel in tanks is prevented from leaking into the water. Is there any way you can decrease the angle the boat is in? You could simply visit a marine service center and ask if you could rent a gas siphon set up. They drain tanks all the time to find fuel problems. Chances are, when you released the pressure on your tanks, the overflow will stop. But when it gets really warm in Spring, you are going to have more expansion, more leaking. Not a safe situation. Good luck.

er
Re: Draining some gas?
Posted: November 20th, 2022, 11:12 am
by tonyiiiafl
That makes sense. Thank you
Re: Draining some gas?
Posted: November 20th, 2022, 12:37 pm
by km1125
This is why they never recommend to FILL the tank(s) prior to storage, but top them off maybe to 75%. With that much fuel, the temperature doesn't swing as much and when it does draw in air from cooling, it will be after most of the moisture in the air has already "dewed out".
Mine didn't have any valve in that path, but it was an older boat. I'm not sure how a valve would stop something that the cap wouldn't (unless it's a vented cap).
You could just remove a fuel line to the engine(s) and use a small electric pump to pump some fuel into a couple 5 gallon cans, just do all the precautious steps to avoid sparks and spills.
Re: Draining some gas?
Posted: November 20th, 2022, 12:53 pm
by tonyiiiafl
The funny thing is, I know I run 35 gallons out on the way to winter storage. However, this year I was not on my game and ran up to storage with teh tanks set on the aft reserve tank! I will never do that again! I had thought of taking the sender out and running the 25' hose out the aft cabin to siphon, but also concerned it I took that off gas may come out of the hole. It sat at the marina in the water for 3 weeks full and never lost a drop. I could also just ask to be placed in water early April too and leave cap a tad loose to allow some venting, but not too keen with that also with the shrink wrap.
Re: Draining some gas?
Posted: November 20th, 2022, 3:51 pm
by Cooler
If you use a pump, avoid an electric pump if possible. One spark and kaboom. BE CAREFUL.

er
Re: Draining some gas?
Posted: November 21st, 2022, 7:39 am
by bud37
tonyiiiafl wrote:Source of the post The funny thing is, I know I run 35 gallons out on the way to winter storage. However, this year I was not on my game and ran up to storage with teh tanks set on the aft reserve tank! I will never do that again! I had thought of taking the sender out and running the 25' hose out the aft cabin to siphon, but also concerned it I took that off gas may come out of the hole. It sat at the marina in the water for 3 weeks full and never lost a drop. I could also just ask to be placed in water early April too and leave cap a tad loose to allow some venting, but not too keen with that also with the shrink wrap.
I would get the yard to pull the extra fuel, they have the pumps and hose etc or should. Just give them the fuel containers to fill and you can use it in your vehicles etc.
Chances are the level in the tanks has blocked the airspace below the vent hose take-off area, you could maybe vent it out the fill, just cobble up something to get the fumes outside the shrink but really you don't want raw fuel sitting in the vent hose and possible leaking at some point over the winter IMO.
Re: Draining some gas?
Posted: November 27th, 2022, 2:24 pm
by tonyiiiafl
I got the gas drained. I bought an electric fuel pump, self priming to 7’. Removed the gas line to engine from the engine fuel pump, and placed the electric fuel pump about 5’ down from engine compartment. I also soldered some alligator clips to the fuel pump wires. clamped off the fuel line and got batter power to the fuel pump, then unclamped. I pumped the gas out to the cockpit. At 35GPH, I let it run for 20 minutes, that t5ook out approx 12 gallons of gas that I pumped right to the aux /stern tank. That I knew was 38 gallons down. Clamped off rubber fuel lines again, reconnected lines, shut off fuel lines to engines, let air out in case of any fumes, although there were none. gave teh old girl a kiss and went home.