Winterization - Onboard Fuel

NelsonQ

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So I've always practiced adding stabilizers to my fuel, particularly for winter or summer storage (snowblower in the summer, weed wacker and mower in the winter) I've even done this with my outboard portable tanks with fuel in them.

So here's the question on storage of fuel.

I have a 26 gallon onboard fuel tank. Should I simply add stabilizer to the fuel with a 1/3 or 1/2 tank?

Or should I fill it completely (of course using proper amount of stabilizer) to prevent moisture buildup inside the tank?

It will be covered but stored outdoors during the winter.
 

erikgreen

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Jan 8, 2007
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Re: Winterization - Onboard Fuel

It's best to fill it completely to avoid giving the ethanol in the gas surface area with which to attract moisture. But, that can be expensive.

Myself, I just stabilize it and make sure the boat stays dry as possible.

Erik
 

rndn

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May 20, 2007
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Re: Winterization - Onboard Fuel

You will get different schools of thought. I have always filled up the tanks with stabilizer for the winter storage and have never had an issue. I firmly believe having the gas react with air will destabilize the fuel much faster than a nice closed environment you get with a full tank. I know it's not really closed but if you fill it right up there is much less surface area of air to fuel.
 

Irv964

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Re: Winterization - Onboard Fuel

If your "not" going to run the stabilizer then either a full or completely empty tank is recommended. I have always added stabilizer to what ever is left in the tank and I have never ran into a problem yet. I also probably add far more than what is req'd but it is relatively cheap and it won't hurt a thing. My 2 cents........Irv964
 

erikgreen

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Re: Winterization - Onboard Fuel

Might want to read up on that Irv... there's an optimum amount to add per gallon of fuel, and having extra can be a bad thing in certain cases (from what I remember... hazy memory here).

Erik
 

chrisg

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Re: Winterization - Onboard Fuel

Might want to read up on that Irv... there's an optimum amount to add per gallon of fuel, and having extra can be a bad thing in certain cases (from what I remember... hazy memory here).

Erik

Oh-Oh!, I just pulled my boats out last weekend, and put stabilizer in the jet-skies for 12 gal each tank, even though they are not full!. I even put stabilizer for 25 Gal in my boat, again there only being between 15-18 Gal in it.

I would not think you can over do the stabilizer ( within limits - I would not put more then the tank's gas capacity amount).

Since we are on that topic again. (Funny how this topic keeps comming up ;)
How about running the engine dry Vs just leaving stabilizer in it?
 

NelsonQ

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Re: Winterization - Onboard Fuel

Thanks for the input. I'm going go with simply adding the appropriate amount of stabilizer to the remaining fuel and hope for the best.

I did this last year on my 5 gallon portable tank with no issues, but I just wanted to see if there was a hard rule of thumb to follow
 

mthieme

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Re: Winterization - Onboard Fuel

It seems like the overwhelming majority of folks in here are big believers in gas stabilizer.
Personally I have never used it, don't believe in it. If something is going to sit for an extended period of time (6 months or more, although I have tractors with fuel in them older than that, they start and run just fine), I'll drain the tank and use the gas in something else. I have never had any problems, which is the reason for my religion.
Not to start a thread war as I'm sure everyone has a horror story, but more out of curiosity for my own edification, I googled how long before gas goes bad. Other than a plethora of opinions I found this on wiki.answers

The risk of gas going stale is often exaggerated. Still, no getting around one basic truth: in principle gas can go bad. The shelf life of gasoline depends on the type of gas and the storage conditions and can range from a couple months to a couple years. One wild card is that gas you buy at the pump may already have been in storage for anywhere from days to months. If you are burning a tank of fuel a month or even every two months you have nothing to worry about. I would however buy my gasoline at a station that sells lots of fuel. That way you will get fuel that has not been stored underground very long. I would also add a can of good Fuel Injector cleaner once a year. Seafoam & Techron are both excellent and sell for around $6 per can. Add the entire can to a full tank of fuel once a year. So don't worry, your fuel is not going to go bad in one month.
 

NelsonQ

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Re: Winterization - Onboard Fuel

My purpose isn't to keep the gas from going bad, it's more on how to keep the moisture down inside the tank and the stabilizer should help in that regard.
 

chrisg

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Re: Winterization - Onboard Fuel

Isn't it to prevent water/ moisure build up? have to check into this, but for $10.00 to do all my boats, thats not much to worry about.
 

mvn

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Re: Winterization - Onboard Fuel

So don't worry, your fuel is not going to go bad in one month.

One month??!? Must be nice! Unfortunately, I just winterized ours (full tank AND stabilizer) and won't get to play with it 'til next May!!
 

Irv964

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Re: Winterization - Onboard Fuel

Might want to read up on that Irv... there's an optimum amount to add per gallon of fuel, and having extra can be a bad thing in certain cases (from what I remember... hazy memory here).

Erik

I know there is a set amount per gal/liter but I am pretty sure I read on the lable that adding extra will not hurt a thing? I know everything has to be with in reason but how do you know "exactly" haow much fuel you have in your tank if it is a built in one?
I have added what I believe is far more than what is req'd to my boats for the past 12 yrs and never had a problem, maybe I got lucky but I just can't see it hurting anything?........Irv964
Just found this, it is directly from Sta-bil's own website: http://www.goldeagle.com/sta-bil/faqs_stabil_marine_detail.asp?product=STA-BIL Marine&ID=191
 

rrhodes

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Jun 24, 2008
Messages
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Re: Winterization - Onboard Fuel

Winter here in SC lasts about 2-3 months (Not swimming and tubing) But running around the lake. In my case if I have a full 55 gal tank do I even need stabilizer?

I am more worried about that little bit of fuel in my outboard going bad I am considering firing up the engine at least once per month during the winter to run that out of the injectors.
 

Irv964

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Re: Winterization - Onboard Fuel

Winter here in SC lasts about 2-3 months (Not swimming and tubing) But running around the lake. In my case if I have a full 55 gal tank do I even need stabilizer?

I am more worried about that little bit of fuel in my outboard going bad I am considering firing up the engine at least once per month during the winter to run that out of the injectors.

2-3 months isn't too bad but why take a chance? Like said above, it is relatively cheap so why not have peace of mind? I believe the main reason for adding it is not for the moisture that may accumulate but rather for keeping your fuel fresh. Once fuel starts to get old it will start to varnish up and you don't want that inside your carb(s) for obvious reasons. A bottle of Sta-Bil is like an 1/8th or less what it would cost to have the carbs devarnished, let alone the headache of pulling your boat and taking it to a dealer or mechanic. My 2 cents, I know I will continue to use it.........Irv964
(P.S. forgot to add, make sure you run your engine for at least 5 minutes after you have added it, that way it gets through the system, including the carbs.) Here's something I didn't know? Not that I won't be running it for that long but still good to know.
http://www.goldeagle.com/sta-bil/faqs_stabil_detail.asp?product=sta-bil&ID=2
 

witenite0560

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Sep 6, 2008
Messages
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Re: Winterization - Onboard Fuel

I thought stabilizers (such as Stabil) were intended to keep the gas from breaking down and leaving that varnish looking gunk in your fuel system, or with todays unleaded fuel it seems to be more of a green gummy gunk. I could be wrong, but to my knowledge they aren't intended to do much for moisture. For moisture you'd be better off with putting a bottle of fuel line anti-freeze or something like that in it, as the alcohol in the mixture will mix with small amounts of water and allow it to be burned. If you're burning ethanol blended fuel even that shouldn't be necessary, since the ethanol will do the same to some degree.
I would say your best bet would be to run out or drain the carb (not sure about injections systems since it's not good to run them dry), shut off fuel from the tank to the engine and fill it full prior to storage with an ethanol blended fuel. A full tank doesn't leave much room for condensation to form, even with the vent open to atmosphere. A partial tank has more opportunity to suck in outside air through the vent, due to temperature and atmospheric changes. Just my .02, but then I live in Idaho where the relative humidity is much lower than where some of you folks live, too.
 

rrhodes

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Re: Winterization - Onboard Fuel

2-3 months isn't too bad but why take a chance? Like said above, it is relatively cheap so why not have peace of mind? I believe the main reason for adding it is not for the moisture that may accumulate but rather for keeping your fuel fresh. Once fuel starts to get old it will start to varnish up and you don't want that inside your carb(s) for obvious reasons. A bottle of Sta-Bil is like an 1/8th or less what it would cost to have the carbs devarnished, let alone the headache of pulling your boat and taking it to a dealer or mechanic. My 2 cents, I know I will continue to use it.........Irv964
(P.S. forgot to add, make sure you run your engine for at least 5 minutes after you have added it, that way it gets through the system, including the carbs.) Here's something I didn't know? Not that I won't be running it for that long but still good to know.
http://www.goldeagle.com/sta-bil/faqs_stabil_detail.asp?product=sta-bil&ID=2


Point made and I don't want my injectors clogging up.
 

Irv964

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Re: Winterization - Onboard Fuel

Came across something last night that may be of interest to us in the great white north and also those who live in colder climates to the south of us?

I happen to have 2 bottles of gas stabilizer, one is Sta-Bil and the other is Canadian Tire's own brand, "Motomaster".
I first read the Sta-Bil's ingredients and then the Can.Tire ingredients and I noticed the Canadian Tire brand of fuel stabilizer also had ispropyl alcohol in it! Most people who live in below freezing climates will know that this is the main ingredient in gas line anti-freeze! Guess what brand I am buying from now on? Plus it is cheaper too!.........Irv964
 

NelsonQ

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Re: Winterization - Onboard Fuel

Thanks Irv.... I just dumped the Crappy Tire version in my tank this weekend when I pulled the boat out. I never read the contents, just used what I always did.
 

Sea Ray

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Jun 18, 2007
Messages
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Re: Winterization - Onboard Fuel

This is always a topic of much debate.

Here are my 2 cents.......The moisture you get in the fuel tank comes from condensation of the air in the tank due to temperature changes.

The more fuel you have in the tank, the less air there is in the tank, so you will have less condensation in the fuel.

SO...If it were me and I was storing my boat outside or somewhere where there is going to be a lot of temperature changes (even sunny days and cold nights). I would fill the tank completely.

However....Come spring, if you run the gas that is in the tank instead of draining it and you have a full tank of stale gas where you have no choice but to run some of it.

IF, you have a partially filled fuel tank you can add fresh gas in the spring before you run it.

I am lucky enough to be able to store my boat in an attached garaged which maintains a fairly constant temperature. I am also not going to drain a 45 gallon gas tank. So, I store it partially full of gas and add fuel to it before taking it out in the spring.

I own snow blowers, motorcycles, weedwackers, lawnmowers, dirt bikes, generators and other gasoline operated "toys". I rarely use Stabil in these items and have never had a problem. BUT, I can pull the carb off of these items and clean it if I have to. I don't want to that on my boat.

Stabil also recommends that you store items completely full of fuel and drain the tank before using. But, most people never drain the fuel.....
 

Irv964

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May 3, 2008
Messages
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Re: Winterization - Onboard Fuel

I took my boat into the dealers yesterday for it's winter nap, while I was there I asked them about filling or emptying the tank and adding stabilizer?

This is what they told me, we have been in business for 20 plus years and have never really had issues as far as excessive water in the fuel or bad gas. They stated they always use stabilizer and have never once told the customers to make sure the tank was full or empty. They also stated the boats with built in plastic tanks are far less prone to condensation than the older metal ones.
They also stated if your worried come the spring, add a bottle or two of gas line antifreeze but they said they have never had too.
(P.S. make sure it is isopropyl alcohol for 2 strokes).........Irv964
 
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