Replacing fuel tank 1988 Overnighter 204c

[evram10]

Hello,
I recently purchased a 1988 Overnighter 20' and upon filling the tank quickly discovered that there is a sizable fuel leak despite being told by the seller there was not and not finding any gas in the bilge upon initial inspection. From what I can see of the lines and fuel water separator I believe that the leak has to be coming from the tank, which is the original aluminum tank. Luckily this model has a deck hatch cutout so I don't think it will be too intense of a project to open that hatch and remove the tank. Just wondering if anyone has done this or has any tips on how to make this process easier or different ways to go about it. A local marine welding shop has quoted me $1300 for a new aluminum duplicate, but I am also debating going with a smaller poly tank. I also suspect I will find some rot when I open the hatch so if anyone has any tips on the threshold for replacing/repairing stringers that would be helpful as well. I believe I got the boat for a good deal as its coming with a 2017 Yamaha 150 with low hours which is primarily why I bought it and I'm not looking to get into any structural repairs/work on the hull. Thanks.

 

[Hookup1]

I'm not familiar with your hull. I have a 1997 268 Islander that I did fuel tanks on a few years ago. At 37 years old I would say you need a new tank. I just had my transom replaced due to water intrusion. You won't know about stringers until you get in there but transoms are generally more of a problem. Poly tank is a good idea. If you get an aluminum tank use a USCG certified tank builder. Make sure it's properly insulated and mounted.

Thread '268 Islander Fuel Tank Replacement'

Jul 10, 2023

Decided that this is the year to replace my 25 yo fuel tanks. No leaks. I plan to keep the boat. I'll document the process here.

Pulled the hatch. This hatch was rebuilt a few years ago with Coosa board. Looks good and feels solid. Hatch was set with 3M 4000 - kept everything sealed. Some difficulty cutting with blade to get it up. Not sure what it will go down with. Deck ports were caulked in from the underside as well. Kept the tanks dry.



I also put plastic over the fill, sending unit and pickup. This deflects any water away from the busy area of the tank.

...

• Hookup1
• Replies: 70
• Forum: Tips, Modifications and Electronics

• 

 

[Jimsalv]

Hello,
I recently purchased a 1988 Overnighter 20' and upon filling the tank quickly discovered that there is a sizable fuel leak despite being told by the seller there was not and not finding any gas in the bilge upon initial inspection. From what I can see of the lines and fuel water separator I believe that the leak has to be coming from the tank, which is the original aluminum tank. Luckily this model has a deck hatch cutout so I don't think it will be too intense of a project to open that hatch and remove the tank. Just wondering if anyone has done this or has any tips on how to make this process easier or different ways to go about it. A local marine welding shop has quoted me $1300 for a new aluminum duplicate, but I am also debating going with a smaller poly tank. I also suspect I will find some rot when I open the hatch so if anyone has any tips on the threshold for replacing/repairing stringers that would be helpful as well. I believe I got the boat for a good deal as its coming with a 2017 Yamaha 150 with low hours which is primarily why I bought it and I'm not looking to get into any structural repairs/work on the hull. Thanks.

I replaced two tanks on 2 different Explorers. You will likely have to re core the tank hatch cover. You will probably have to do some minimal cutting toward the rear of the tank, narrowing the "sill" that the hatch sits on. You must fully drain the tank, carefully! I found a decent non static fluid transfer pump on Amazon. You will have to be creative on how you get the tank out, there will be old wooden wedges holding the tank in place. Once you get the tank out, the "coffin" should be solid. (mine was on both 92's) DO NOT go with poly! Get the tank from your local shop, in New England it's always Luther's Welding for me. Don't cut the fuel lines, when you replace them, use them as "snakes" by attaching the new lines to the ends and pull them through, this is painful bit the best way to get the lines where they go. You may have to put an access plate to get at where the fuel fill is. It's definitely a process, but if you are handy, you can save a ton of money doing it yourself. PS. listen to the tank manufacturer on what to do with the new tank before install. The first tank, Luther's told me to barrier coat the tank. Four years later (22) they told me not to do anything with it because too many people were not doing the coating properly and water got in and stayed against the tank due to bad coating job. They should give you a couple strips of coosa board that you cut and affix to the bottom and sides of the tank with 5200 for it to sit on. Good luck, this is all advice and hopefully some guidance that you will use.