Gas leak?

[Dan]

I'm looking for some opinions here. Here is the situation. I have an '88 23'cc. A couple of weeks ago, I topped off my 130 gal tank based on what my Navman fuel meter said I needed. This past weekend, I was doing a prefish boat check and noticed gas leaking out of my bilge drain. I proceeded to pull the aft deck panel out and discovered about 1.5 gal of gas in the bilge. I removed all of that gas and waited til the next morning to find more gas in the bilge. I did not notice any leaks around the sending unit, filler hose, or the vent hose thru the small area of the inspection plate. Thinking the worst I assumed I have a leak in the tank which will require the obvious tank removal. Yesterday evening, I was going to start by pumping the gas out of the tank by removing the sending unit and inserting a hose thru the hole on top of the tank. When I took the first screw out, gas shot up thru the hole about 6", so I immediately put the screw back. I then decided to go thru the 90o elbow that the filler hose was attached to. Gas started leaking out of that as soon as I started loosening the clamps. I then went thru the gas filler cap. You get the picture. The tank was FULL. Anyway, I proceeded to pump 50 gal out of the tank into a 55 gal drum and cleaned up all the gas that leaked into the bilge. I set the sending unit back in the tank and it still reads almost full. It should be reading a little less than 2/3. It has been more than 24 hrs and the bilge is bone dry. What do you guys think? I'm thinking the tank was overfilled and leaking out of the vent hose or the sending unit. I replaced the filler hose 2 years ago b/c it was dry rotted, but the vent hose, I assume, is original. And I do not remember the brand of gasket sealant I used on the sending unit, but I never was happy w/ it. I am going to continue to pump out all of the gas into drums to see out much I actually have. The Navman fuel meter may need to be calibrated. Sorry to be long winded. All opinoions are wanted.

Danny

[hermco]

If you have fuel in the bilge it is leaking from the fuel system. The only place you should ever see fuel leaking is from the vent during normal temparture changes and expansion of the fuel and gassing in a full tank.The pressurization makes me think you have a vent problem. I have seen something as minor as a dead wasp stuck in the vent fitting that stops the tank from venting. Do you have any trouble filling the tank? Does it only leak when full?

[Dan]

Hermco
Yes, I do have some problem filling the tank. I cannot fill the tank any faster than the first notch on the nozzle or it will back flush b/c it does not vent fast enough. I have owned this boat 6 years now and this is the first time I have ever seen gas in the bilge.

Danny

[Finster]

Sounds to me like your fill might be kinked or squeezed and leaking at those presure points. After time all full/vent line dry rott, but if it's pressed it will quicken at that point.
I've replced many fills that have put an unthinkable amount of fuel in the bildge.

[hermco]

OK. I would start diagnosing with the vent thru hull fitting. Check that the vent thru hull is not blocked and if not then replace the hose. Not easy but if you can avoid a major fuel system rebuild by doing this I suggest you try.

[hermco]

Unthinkable amount?
Wow!
I can't even begin to think about how much that is.......

[Finster]

hundreds and hundreds of gallons....

I've replaced two fills that pored a gallon or more into the bilge. And IMO any amount fuel in the bilge is a concern. But I wouldn't start yank'n tanks without checking the fill or vent....mr.freak'n expert! [img]/forum/images/graemlins/tongue.gif[/img]

BTW, the vents on my work-boat go into the cockpit, right where they should be!

[Dan]

Thanks HermCo. I agree. I will start w/ the vent hose and thru hull hoping that is all it is. I've been going over in my head what a tank replacement will entail. Disconnecting all wires, cables, & hydaulics plus removing the console etc. Sounds fun....NOT.

Danny

[hermco]

I've replaced two fills that pored a gallon or more into the bilge. And IMO any amount fuel in the bilge is a concern. But I wouldn't start yank'n tanks without checking the fill or vent....mr.freak'n expert!

Sounds like you would be needing another helping of FREEDOM FRIES young man! Or maybe a serving of FREEDOM TOAST tomorrow morning?

I am not and do not profess to be an "expert". Just a guy trying to interact with my fellow man. If you have a better way of how to diagnose a fuel system problem/leak please enlighten us.

[Finster]

Oops. After thoroughly reading your first post. Don's right.