Fuel tank questions

tmarshall · Post by **tmarshall** » Thu Apr 22, 2010 6:22 pm

I know there is a ton of stuff posted regarding fuel tank replacement but, I cant find anything on this matter. I am pretty sure my tank is leaking. not one hundred percent sure but sure enough to start figuring out what I am gonna do. I always have fuel in my bilge after running the boat. After I run I throw a absorbent roll in the bilge and it soaks it up. when the boat sits no fuel accumulates. After it sits for weeks with no fuel accumulation, I run the boat for a half hour and there is fuel in the bilge. I cant find any leaks anywhere. I am gonna have my CAT guy come out and take a look but I am pretty sure hes gonna tell me fuel tank. My question is this: Has anyone built a new fiberglass tank for their boat. I do understand there is a lot of testing and certification required to replace a tank legit. I am just weighing my options at this point. For those of you who have had tanks made, what did you pay? Anyway any advice or guidance would be greatly appreciated. Thanks!

franklyprice · Post by **franklyprice** » Thu Apr 22, 2010 7:53 pm

Thom, As far as I know there just hasn't been enough interest in the new glass tanks for any one to make them. The stainless guys seem to have lost interest also so it looks like if you really need to replace it, it will be with aluminum. I would guess you'd have to spend at least a couple though. From your description of the problem it sounds much more likely to be a return fuel line , not the tank. Have you traced both return lines back to the tank? I do know of a decent original takeout here locally looking for a home. The guy had a local fab shop make a new one from aluminum, as a pre-emptive measure and the good original one is here . It's out of an '86 I think , not sure of your year?

buzzk · Post by **buzzk** » Fri Apr 23, 2010 4:21 am

I'm with Frank, it doesn't sound like the tank is leaking to me. It sounds like a fuel return line. Buzz

Post by **dougl33** » Fri Apr 23, 2010 5:36 am

I'd bet $1000 the tank is not leaking. Think about it. If it were leaking you'd have fuel in the bilge all the time, not just after running the boat. Its a line. It has to be.

lwrenn · Post by **lwrenn** » Fri Apr 23, 2010 2:22 pm

Throttle body seal leaking and it runs down the engine to the bilge. How much fuel is leaking? A little smells and looks like a ton. Look at the top of your engine and see if there is any fuel puddled if so I bet that seal is bad and make sure you do the retro fit of drilling the line and adding the check valve.

Rick · Post by **Rick** » Fri Apr 23, 2010 2:29 pm

He's thinking that the leak is somewhere near the top of the tank and when the boat shifts, he's spilling into the bilge. But I agree with Doug, very unlikely it's the tank. Let the CAT guy do his thing and if he doesn't come up with anything, then pull up your deck and take a look. If it's leaking, you'll be able to see it. I had a replacement Stainless tank made for $3,100 but I don't think the guy is making them anymore for whatever reason. It's also my tank that Frank is talking about.....it's an '85....think the tank was actually made in '84. Don't concentrate on replacement tanks....I think your leak is somewhere else. Rick Ticket 85 SF Merc 454 MPI's Falmouth, MA

kwinters · Post by **kwinters** » Thu May 06, 2010 6:49 am

Having just replaced my tank in october let me tell you what I found. The tank was creacked due to a severe wake inpact but where it was cracked is what you need to look for as it will only exhaust fumes and not fuel. On each side of the tank about midpoint from to back there is a place where the tank has bracing that runs from the tank to the upper outside stringer. This is hard to see and in at the very upper 12" or so or the tank. The cracks developed in the raduis where the tank an d the brace come together. You would only smell feul unless you had your tank totally full or at least higher than 12" or so from the top. Mine was cracked on both sides and after filling up I found fuel in the area where the stringer and this brace come together. The fuel will collect there and not go to the bildge which really threw me off trying to find it. I replaced with a $ 3,800 alum. tank and a lot of labor. abs 1/4" plate and I epoxy coated and pressure checked. Also, I added 2 return tinnings in the top for diesels if I ever repower. Good Luck.

kwinters · Post by **kwinters** » Thu May 06, 2010 6:53 am

Sorry, I just realized I was in the Sportfish forum. I have a 33 convertable. Don't know of the tank design is the same.

Rick · Post by **Rick** » Sat May 08, 2010 3:43 pm

They are not the same tanks in terms of dimensions but look the same in terms of construction. Rick Ticket 85 SF Merc 454 MPI's Falmouth, MA

franklyprice · Post by **franklyprice** » Sun May 09, 2010 6:52 pm

By the way Rick, The tank I mentioned actually is out of an '86 convertable. I'm not sure but it may be the same as a SF. I suspect that after a certain date Bertram made them the same for each boat? Just a guess.

Rick · Post by **Rick** » Mon May 10, 2010 4:31 am

Frank, That would only make sense as it would lower their inventory costs. But maybe with everything else falling apart the tanks were noise compared to other problems. Rick Ticket 85 SF Merc 454 MPI's Falmouth, MA