Gas Tank Presure Leak (I think)?

[thenewguy77]

--------------------------------------------------------------------------------

Brand new to this. Just bought a used 1992 Maxum 1700/XR with a 60HP Merc. Boat and motor runs great minus a few fixes I need to work on (gas guage and odometer don't work). Anyway, the fuel tank leaks out the tank vent in the back. Very slow drip, but I figured with it sitting in the garage on a hot day pressure builds up and that can happen - so I loosened the tank cap figuring that would help with any pressure issues. That did stop it but after the last time I had it out, I did the same thing - but then found the gas level in the tank rose enough to start trickling out the top. Sealed that up and now back to the vent slow leak.

From looking around there are quite a few knowledgable folks on here. Any assistance would be greatly appreciated.

Thank you

 

[rwidman]

Re: Gas Tank Presure Leak (I think)?

--------------------------------------------------------------------------------

Brand new to this. Just bought a used 1992 Maxum 1700/XR with a 60HP Merc. Boat and motor runs great minus a few fixes I need to work on (gas guage and odometer don't work). Anyway, the fuel tank leaks out the tank vent in the back. Very slow drip, but I figured with it sitting in the garage on a hot day pressure builds up and that can happen - so I loosened the tank cap figuring that would help with any pressure issues. That did stop it but after the last time I had it out, I did the same thing - but then found the gas level in the tank rose enough to start trickling out the top. Sealed that up and now back to the vent slow leak.

From looking around there are quite a few knowledgable folks on here. Any assistance would be greatly appreciated.

Thank you

I've never seen a boat with an odometer!

If your gas tank is leaking you should be able to see the leak. If it's a loose fitting or hose you should be able to tighten it, replace the gasket, or whatever it takes.

If you're filling the tank so full that the fuel expands when it gets hot and runs out the vent or filler tube, you're overfilling the tank. Don't fill it so full and you won't have a problem.

If there's a crack in the tank or where a fitting connects to the tank, you're going to need a replacement tank.

 

[thenewguy77]

Re: Gas Tank Presure Leak (I think)?

See, I am the new guy (odometer)

It leaks out the vent in the back a couple days later even after I have been on the water for a couple hours so I don't think it is over filling. I will check the plumbing.

Thanks for your reply!

 

[dickymoe]

Re: Gas Tank Presure Leak (I think)?

i would first definitely find out if the tank is leaking.that can be a major problem if its below a deck w/ gas vapors.i will only fill my tank at the most to 90 95% capacity to allow for expansion on hotter days.as the other poster also advised i would check every hose and fitting near your fuel tank.

 

[JimS123]

Re: Gas Tank Presure Leak (I think)?

I've never seen a boat with an odometer!

I have an Eagle Sonar unit complete with temp and speed sensors. The display can be customized and one of the options is an odometer. I use it all the time. How else would you know how far you went?

 

[Auger01]

Re: Gas Tank Presure Leak (I think)?

It sounds like it may be siphoning out somehow. You might want to install one of those check valves in your vent line and see if that fixes it.

http://www.iboats.com/Attwood-Fuel-...42577968--**********.780382548--view_id.37945

Something like that might work well.

 

[rwidman]

Re: Gas Tank Presure Leak (I think)?

It sounds like it may be siphoning out somehow. You might want to install one of those check valves in your vent line and see if that fixes it.

You can't install a check valve in a fuel tank vent line without causing problems. The vent lets air from the tank out as fuel is added to the tank and the vent lets air in to replace the fuel in the tank as it is used. It also lets air in and out as the fuel expands and contracts with changes in ambient temperature. The vent must be free to flow in both directions.

 

[jeeperman]

Re: Gas Tank Presure Leak (I think)?

Check to see if there is a dip in the vent line real close to the outlet.
(Like the trap pipe under a sink.)
Maybe there is fuel in that trap that is being slowly pushed out by air pressure in the tank.
It would still allow air flow back and forth, it would just require more effort.

Open the filler and with your lungs blow like crazy thru the vent line. If there is, you will hear it gurgle.

 

[Fed]

Re: Gas Tank Presure Leak (I think)?

Lower the front of your trailer as far as you can.