Fuel Leak on my 215DC

[Grizzly65]

New fuel guage and sender, seadek installed, alarm system working, and ready to fish. Filled my tank up (around 80-90 gal) and hit the water. Made it around 10 miles off Galveston and noticed a strong gas smell. Checked the bilge and see six inches of fuel. My boat has always had a very light smell of fuel/oil but never anything visible. Could fuel have leaked into the coffin during fill up and then found a way into the bilge while underway? When I got back to the ramp there wasn't very much fluid in the bilge, and the fuel guage said 3/4. Is it a hole in the upper part of the tank, split fill hose or vent. In the 215 DC  there is no way to really check the tank except maybe by camera. What do you think? I don't want to cut my deck. Maybe put a new smaller tank in the ski locker? It is a polymer tank.

[RickK]

If you have a poly tank they always permeate the fuel smell through them. So a slight smell would be normal.  They are pretty tough tanks too, so for it to leak 6" of fuel into the bilge seems weird.  Something became disconnected, like the vent and all that rocking and rolling on the way out sloshed a lot of fuel out?
I'm afraid you'll never know until you cut into the sole.  Does your sole have a line showing where the fuel tank is and where to cut?

[Grizzly65]

There isnt an outline for the tank coffin. I am going to attempt to get  the dimensions of the tank tomorrow. When filling the tank I do remember hearing a change in sound and i backed off so I wouldn't overfill. it still took an additional 5 gallons or so. is it possible that the fuel did not back up into the fill hose and was pouring out another way? i thought there was only the fuel fill, fuel fill vent, pickup hose and sender hole in the tank. Is there another vent hole that could be open?

[RickK]

Anything is possible unfortunately. You listed the possible connections - so who knows what happened.

[Capt. Bob]

As Rick stated, anything is possible. The sender may be leaking and I've seen a poly tank that the corner chaffed and leaked (I'll try and find the thread).

Tank failures usually manifest themselves when the tank is full/nearly full and the fuel bangs around inside. This is especially true with corroded aluminum tanks where the added weight of the fuel causes the tank to shift in the coffin and the corrosion breaks loose. In your case, that shifting may have exposed a corner that has been rubbing inside the coffin for some time.

Additional thoughts.

https://classicaquasport.com/smf/index.php?topic=12511.msg126230#msg126230
https://classicaquasport.com/smf/index.php?topic=14933.msg146311#msg146311
https://classicaquasport.com/smf/index.php?topic=14263.msg141611#msg141611
https://classicaquasport.com/smf/index.php?topic=11147.msg109788#msg109788

Good luck.

[MaggieRose]

I have a 97' 215 Explorer and I believe your hull and tank layout match mine. My fuel access panel is in the middle of the hull just aft of the livewell. The fuel sender is slightly off-center (port side) when the access is opened. most of the tank extends forward. My hull is fitted with a 99 gallon, cross-poly Moeller tank, Model 9902. I located the schematic of a model 9901 Moeller tank online and will attach it. If you have access to compressed nitrogen (or any other inert gas) you can seal or block tank connections and put a pressure test (no more than 1-2 psi) on the tank. This will verify that the tank is tight. Each hose; filling, vent and engine would have to be tested individually.