Will Gas 'Keep' in Built - In Gas Tank

J

Jeff H

New member
Hi all,

I'm going to be building a Scaup in the new year and I'm getting things lined up.

While discussing the build with my Dad and some friends at the deer camp last week I mentioned that I wanted to install a built in gas tank. My Dad (and another buddy) expressed some concern with the gas gumming up and getting 'bad' if it stays for extended periods of non use. I pointed out that if I used gas stabilizer there would/should be no problem. Apparently, with the addition of ethenol to the fuel there can be more problems experienced and the stabilizer doesn't work very well.

I'm located near Toronto in Canada...there may be differences in the fuel quality from area to area - I'm not sure.

I'd love to hear from some of you and get some other opinions.

Thanks,

Jeff
 
Jeff,

I've been told by my boat dealer that ethanol blended fuels do not store well for extended periods. I'd say you will be fine using a stablizer but would still stay away from ethanol blended fuel for boat motor use.
 
I've been told to stay away from Stabil and others like it and instead store with Sea Foam in the tank. No problems doing it this way for quite some time.

I also find that the motor that the gas is going into makes a difference in what kind of gas can go through it. My outboard works ion just about anything. My dirtbikes the gas better be fresh or else I'm going no where. Same thing with my small 2 cycle motors such as leaf blowers and my mini mud motor. Better be fresh stuff.

Mark W
 
Working in a boat dealership for many years, I can say yes you will eventually have problems if you let your fuel sit for long periods of time, especially with the higher amounts of ethanol they put in all gasoline today. Mark is correct by saying stay away from Stabil and other automotive fuel conditioners, you will have much better luck with the marine fuel conditioners. What ethanol will do, especially on older tanks/motors/fuel lines, is break loose any built up varnish/gunk/whatever you want to call it and let it float in the fuel and eventually reach your motor. If you have a carbureted motor this means more than likely pulling your carburators off and cleaning them, which may or may not be a daunting task for you. What it does mean at the very least is that it will ruin one or more days of hunting for you. If you have a fuel injected motor this could mean very costly repairs/cleaning. Also, if you have a fuel injected motor, you NEED to use a 10micron or finer spin on fuel filter mounted inside your boat, the fuel filter on the motor is not enough.

The simple answer is if your fuel is older than 6 months (engine manufacturers will tell you 1 month) then just syphon it out and discard it. If you dont use your boat every month then always keep fuel conditioner in the fuel, that way the fuel in the tank, fuel lines and motor is all protected for a longer amount of time. In any case, having a spin on fuel filter (carburated or fuel injected engine) will greatly reduce any future fuel problems you may see.

Good luck with the build. I built a Scaup a few years ago and absolutely love it every time I use it.
 
What kind of motor are you going to use..2 or 4 stroke? It seems gas with oil mix seems to get gunky quicker, more so in the carb bowl. Unless it is going to be a big tank, I would think you would use the gas quick enough to not have problems. Ethanol has alcohol as you know and it sucks moisture into it and the additives in it cook off quicker than good old gas. I rue the day when all I can get is corngas.

I have a 3 year old pontoon with a 25 Honda 4 stroke and an 18 gallon built in tank. Last spring I started having motor problems that quit when I hooked up a 3 gallon tank with new gas. If I had ever filled that 18 gallon tank, I could have driven the pontoon to St. Louis from here. I took the big tank out and just used the small one all summer..only re filled it once.
 
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My boat service guys prefer that I deliver my 23' to them for pre-winter service with low amount oif fuel. I'm not sure what brand of stabilizer they use but filling up my 50 gallon tank in Spring "thins" out the old gas.

I would not consider a built in gas tank for any boat under 19 feet long. Why not keep it simple?
 
They now sell a stabilizer by store n start thats made for marine engines,it's supposed to be pretty good. I have never tried it myself,I always use the standard "red" stuff
 
Thanks for the replies folks...just got back from the deer hunt and haven't been able to read/reply till now. Not sure yet whether it'll be a two or four stroke engine but do know that I'll have to re-think the built in tank and what I'll put in the chosen tank.

Really appreciate the replies...talk to you all soon and I'll post pics once the build gets under way

Regards,

Jeff
 
I agree with Gary 100%. If you have a portable instead,when the tank starts leaking, as all built in tanks do eventually you simply buy a new one.If not you will have to cut out the old one and replace it.

I have used several different types of gas treatment over the years to prevent gas line freeze up with no ill effects. Stabil has just come out with a new "marine" version that I will be trying this year. If untreated gas gets too old it will form shellac on your carbs. If you have an oil injected motor or a 4 stroke you can use unmixed gas in your lawnmower or even your wife's car before it gets too old if you fave portable tanks. You can of course pump out the gas in a built in tank but wow that is a pain in the wazoo.

Stay away form built ins unless you are running inboards in a really big boat.

Regardles of tank type install a fuel water seperator somewhere between the tank and motor and check it for water often. Keeping water out of the cylinders will save you from costly rebuilds or scrapping the motor.

Best,
Harry
 
See my blog. I have some comments about what you can do with portable gas tanks. I bought the Moeller 9 gall... it's awesome.

We have similar sized boats.

Plus, I need more traffic for my sole advertiser -

"Bill's Bondage Emporium" 5 cents a hit, so hit often.
 
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