Making my own fuel tanks?

[Clint KY]

With my old 6HP motor the Trolling Motor Battery and fuel tank took every bit if room behind the rear seat. With the addition of my new (to me) 25HP electric start motor, I am at a loss on how to arrange the two batteries and fuel tank. Both the tanks I have are 6 gallon, with the older original OMC tank barely fitting and the newer after-market not fitting at all. I checked the dimensions of the Atwood 3 Gallon tank and even it will not fit due to the transom brace running from the floor to the transom in the center of the boat. Do you think it would be possible to build my own tank(s)? Here is the idea: I can find lots of two gallon gas cans used for refueling lawn equipment that will fit between the battery box and the transom brace on each side. I could add the proper fitting to the tank with a rigid plastic hose running to or near the bottom of the tank. There are many videos on YouTube showing the procedure for adding external tanks to generators for extending the run time. I am considering making two, one for each side and run off one until empty and then just switch the fuel hose to the other.

Is there any holes in my logic?

 

[surfman]

It would work but if not done properly could be risky for leaks and then potential disaster, not sure if they would be approved by the LEO.

I would move the batteries up front.

 

[Johnny]

Clint, many years ago, (1980), I fabricated a 40 gal. fiberglass tank for my 20' fiberglass boat.
It worked well with no leaks for 2 years then I sold the boat, so don't really know how
long the tank lasted for sure.

The reason for my response to you is this ...... if you do decide on a size and style of
tank and you decide to make it yourself .... please design a 4" to 6" inspection plate / access port
so you will have access to the inside of the tank. It will be worth your while, believe me.





There is nothing more grand
than to be just messing around
in an old boat. POGO - 1960

 

[Clint KY]

I am going out today to see if I can find one of the 2 Gallon Safety Gas Cans. The dimensions listed online are 11.25" in diameter and I will have 11.5" X 13" on one side if I use a Group 24 size battery for my starting motor.

It being a manufactured gas can it meets the government requirements, although my modification to it probably will violate some element of the regulations.

Now the question is: How long can I run my new to me 25HP Evinrude on 2 gallons of gas. The prior motor, a 6HP would run all season on 6 gallons, though I never mixed that much at a time.

 

[WVfishnfool]

Look at this Moeller 3 gallon tank on Bass Pros website. It may be just what you need. I bought this and have it in my 1436 MonArk on one side and the trolling batt on the other. Here's the link: https://www.basspro.com/Moeller-Marine-Products-360-Series-Portable-Fuel-Tanks/product/10210684/

 

[lckstckn2smknbrls]

The basic formula for fuel usage is 1 gallon per hour for every 10 horsepower at WOT. A 25 hp motor will use about 2.5 gallons per hour at WOT.

 

[Stumpalump]

Have you searched fuel tanks, aux fuel tank and racing fuel cells? There are hundreds of different tanks available. Here is a source for odd tanks. https://justgastanks.com/index.php?cPath=149_329&osCsid=fb202c83824feb859616ddbb8edf60dd
Check Jegs or summit racing as well.

 

[flatboat]

Sometimes if there isn't room behind the seat you have to move the tank to the front of the seat . I don't think I would mod a gas can to make a tank for a boat . In the middle of a lake is not where I would want to fight a fire or try to swim away from burning gas on the water . Boating safety is not to be taken lightly , you life may depend on it !
as always, just my take on it
Ed