Pontoon Boat & Deck Boat Forum

I brought this topic in another thread, but I ended up getting sidetracked, and the discussion drifted towards other topics.

If you look at my pics below you can see the red 12 gallon gas tank sitting on the back deck. It was added on by the previous owner because he said that the original tank was getting water in it.

I want to fix whatever was causing the water to get into the tank so that I can use the original tank, and use the red tank as a secondary gas tank to help increase my range.

Any ideas? Suggestions?



If I can get both working I should have a range of close to 100 miles...probably won't go that far but who knows...






I use the red tank as my primary tank now, but want to use the original as well.



Red tank is 12 gallons and I think the original is about the same.


This is the original tank located just below the fuel/water seperator.

Is there water in the tank now. You could put low pressure air in it and check it out, or pull it and have it checked. By low pressure I mean 2 or 3 lbs of air. Hard to believe it's getting water in it with out obvious cracks or connections needed to be resealed. Shouldn't be rocket science to find.

I know that there is a gas tank repair sealant that can be poured into the tank to seal leaks. Small engine mechanics use it all the time on lawn and garden tractors. I've never used it personally but I would think it would work on a boat also. It might be something to consider.

Where is the tank located? Can you get at the top of it?

Somebody didn't look at the pictures

I can't believe a topic got side tracked here

Anyone know anything about tap fins?



UMMMM sorry. First take those plastic hose clamps off and get 2 SS clamps for each connection. Check the seals on the gauge wiring area. Transom gas tanks to me are trouble just waiting With all the spray and water hitting there, I think water will get sucked in somewhere.

Yellow, that is the 12 gallon tank Ron is using now. Where is the OTHER tank?

GregF wrote:Yellow, that is the 12 gallon tank Ron is using now. Where is the OTHER tank?

Last two photos show original tank in the transom pod, under the deck below the fuel seperator, in front of the motor.

right below it in the transom, gregf

Looks like a Moeller plastic tank, unless it's cracked or the hose fittings are loose I'd clean it out, put fresh gas in it and give it a go. To properly inspect it you're going to have to drop the engine pod down.

Pull the old tank, plug all the outlets with test tube stoppers, synthetic wine bottle corks or whatever. Put 2 psi of air pressure in it, spray the outside with Leak Tek Detector Spray (commercial stuff) or a few drops of dish washing liquid and water in a spray bottle. You'll find the leak.

I would be surprised if its the plastic, most likely a fitting.

GregF wrote:Yellow, that is the 12 gallon tank Ron is using now. Where is the OTHER tank?

See my previous comment

Hint............not all gas tanks are red

Sorry man. I'm feeling froggy today

Sorry, I should have looked at he pictures more. You can get a free look into that tank by pulling the sending unit. The round doodad with 5 screws in it.
Use a turkey baster to suck out all the crud and old gas.

If you have one of those MANUAL bilge pumps that will work too. The piston thing like a backward bicycle pump.
Try to wipe it out as best you can.
Look around under the deck and see what they did with the vent hose. That is probably where the water is coming from. If there is no holes poked into this tank I doubt it is really bad. They are pretty tough.
I would try to make sure the end is where it won't get water in it. Maybe make a little dog house for it on the back of the boat. (inverted can with the hose stuck up inside). Your water separator should take care of a few drops now and then.

Use some ultra black gasket maker when you put the sender back in. If Yellow is right, that it is leaking around a fitting, that will be the one.

Thanks for the tips guys. It looks like my fuel/water seperator had two available connections. Is this designed to accept two tanks?