How Do You Store Your Outboards: Stabil, Drain The Tank?

[tcbass]

I've had a 2000 Mercury 115 horse (2 stroke I think) for about 2 years and I've always put Stabil and Seafoam in each tank when I fill up. I was told that gas starts to break down in about 1 week and if you want put Stabil in after that it's too late.

 

I put Stabil and Seafoam in each time I fill my tank up for that reason and because if something happens to me and my boat needs to be stored the gas will be prepared properly. Recently though I've heard that you shouldn't do that, what you should do is completely drain the tank each season before you store it. (I know those of you in certain states don't have this problem as you can use your boat all year long).

 

 

 

So which is best for when storing your boat and motor:

 

 

 

1.) Put Stabil in the tank prior to storage (I usually have 3/4 to a full tank)

 

 

 

2.)  Empty the gas tank

 

 

 

I haven't had any problems yet, but that doesn't mean I won't.

 

 

[Scott F]

I've had the same engine for 20 years and typically put it away for at least 6 months during the winter. I add Stabil only after my last outing of the year. I have never had any issues with gas problems. I certainly would never drain the tank.

[Long Mike]

I've been using a gas stabilizer (Startron) for 10 years and have never drained my tank, although the boat has gone months without use.

[CRANKENSTIEN]

I've heard a lot of different theory's from what I would consider reputable sources. I put in stable fill the tank and even leave gas in the engine. Never a prob on a vmax 150.

[junyer357]

After having the carbs gum up over the winter a few years back i talked to my trusted mech. He said for our motor (93 'rude intruder 150) to simply put water hose attachment on, crank motor and then pinch off fuel line right past primer bulb. Run it til it quits and wont turn over. Then simply pull plug on foot to make sure no water is in it and let it go for winter. Since we have began doing that it takes a few min to pump primer bulb to a "full" feeling but boat fires off like we used it a week ago, not 5 months. Ours isna 45gal tank with no access so draining tank isnt an option.

As far as fill ups go ive never had a problem with gas going bad in a week. If it is you have other issues present most likely such as a bad tank or bad gas Letting in too much water. We do try and put some marine stabil in at each time we get gas, mostly because we dont always trust wether the gas is 'ethonal free' as it claims.

[S Hovanec]

I run stabil all year, but for winter, i put stabil in the tank, run the motor to ensure the stabilized gas is in the lines, then I drain the tank and run that gas in my truck, car and snowblower.

[Al Wolbach]

I am not an expert but I have read a lot on this issue, which are really two issues.

1. How fast does gas lose it's octane rating. I have read that gas starts losing it's octane in a week or two but that does not mean that it will not burn and after even a couple of months you may not notice the loss. There are to many variables to say for sure when gas should no longer be used. Engines are different, storage areas are different, boat tanks are different, even gas is different and on and on. If I leave gas in my weedeater a month it won't start until fresh gas is added. Do what works for you and gamble what you can afford to loose. My bass boat and pontoon boat both have engines that would cost $12k and $20k to replace. I use Seafoam and satbil out of self defense, simply I can not afford the loss/repair, down time etc., plus they have other benefits such as decarbon the cylinders. So, place your bets

2.Here's my take on the full or empty gas tanks for storage. The problem of gas breaking down can easily be taken care of by adding stabil, startron etc. The big problem as I understand it, is the introduction of water to ethanol gasoline and this can be prevented 2 ways that I can think off. Gas does not have water in it so the source of the water must be the air in the empty part of the tank. So condensation must be the cause of the water. A full tank has no air(or very little) so that is one fix to prevent water. An empty tank that is very well vented allows the air to stay the same temp inside and outside so therefor no condensation, no water, no 2 fixed. One problem with empty tanks is the vents do not always allow enough air to move freely to prevent condensation. So removing the fill caps is the only real fix for empty tanks exposed to temp changes.

My advice is, if you have portable tanks take them indoors(garage, shed) and store empty with the fill caps removed. If you have built in tanks store them full with a stabilizer of your choice. I would also recommend adding a water separator(about $25) as cheap insurance. JMHO...........Al

[kjfishman]

I read somewhere that aluminum gas tanks have a problem with condensation if not full.  The tank in my boat is plastic but I still do as others have mentioned and drain the tank at the end of the season. I use the gas in lawn equipment and my snow blower. I drain the tank by disconnecting the fuel line from the connector on the motor and use the primer bulb to drain the tank into gas cans.

[Crappiebasser]

I run my outboards year round so it's not an issue. My ski boat gets ran down to about 1/8 tank the gets stabil.

[Siebert Outdoors]

I won a bunch of Lucas Oil Fuel Stabilizer in a tournament so I've been using that for the last year.  I add as much stabilizer as I put fuel in. 

[Sam]

Run gasoline out of motor.

 

Fill tank as full as I can.

 

Add Marine StaBil to boat's tank.

 

Never have had a problem other than after ten years the short fuel line in the Mercury rotted out and had to be replaced.

[GoldEagle]

Hi everyone,

 

We work for Gold Eagle Co (makers of STA-BIL®) and wanted to help clear up some confusion.  The comments about keeping the fuel system full are correct.  The best practice when storing equipment is to fill the tank about 95% full, add a high quality fuel stabilizer, and run the engine for a few minutes to ensure the entire fuel system is treated.  It is almost impossible to completely drain the tank.  Even the smallest amounts of gas will gum up and can clog parts of the fuel system.  Also, the more open space you leave in the tank the more susceptible the metal components of the fuel system are to rust & corrosion from condensation.

 

Please feel free to reach out if you have any questions.

 

Have a great day!

[nicksmurf111]

I use my current boat for winter hunting, so the outboard doesn't sit for more than a few months.  I don't worry about STA-BIL unless I know an engine/gasoline is going to be sitting for months.  So, my generator gas, my LAST lawnmower fill-up, and stuff like that when I know I won't be using the gasoline for months.  Even then, if you have a 6 month old gas can worth, pour unmixed gas into your vehicle (or mixed gas into my lawn mower if possible) and re-fill it.  I think some of the outboard oils already have stabilizers built-in.  What will kill any carburetor is water in the gasoline.  NEVER store a gas can outside in the rain.  Also, they sell ethanol free recreational fuel where I live.  I plan to use more of it in my outboard, but am a little concerned about water not being absorbed (lack of ethanol to absorb it).  Any condensation/water contamination will separate to the bottom of the tank and get sucked into the pickup.

[Al Wolbach]

I use my current boat for winter hunting, so the outboard doesn't sit for more than a few months.  I don't worry about STA-BIL unless I know an engine/gasoline is going to be sitting for months.  So, my generator gas, my LAST lawnmower fill-up, and stuff like that when I know I won't be using the gasoline for months.  Even then, if you have a 6 month old gas can worth, pour unmixed gas into your vehicle (or mixed gas into my lawn mower if possible) and re-fill it.  I think some of the outboard oils already have stabilizers built-in.  What will kill any carburetor is water in the gasoline.  NEVER store a gas can outside in the rain.  Also, they sell ethanol free recreational fuel where I live.  I plan to use more of it in my outboard, but am a little concerned about water not being absorbed (lack of ethanol to absorb it).  Any condensation/water contamination will separate to the bottom of the tank and get sucked into the pickup.

I do not know of any outboard oils that have stabilizers in them since most are not premixed any more. Most oils for weed eaters, chain saws, etc do have stabilizers in them however. The cost of Stabil is cheap insurance to me compared to time/expense of repair or clean/rebuild. Why gamble to save a few dollars......Al

[nicksmurf111]

I do not know of any outboard oils that have stabilizers in them since most are not premixed any more. Most oils for weed eaters, chain saws, etc do have stabilizers in them however. The cost of Stabil is cheap insurance to me compared to time/expense of repair or clean/rebuild. Why gamble to save a few dollars......Al

 

That's what I was thinking.  The outboard oil doesn't say anything about it, but most of the weed eater/chainsaw oils do these days.

 

I've never had a carburetor clog up on my watch, but I'm rather young too.  I've cleaned many, many, in engines I've gotten used.  I really think it is mainly is due to water/condensation, not fuel going bad in weeks time.

[LuckyGia]

I attach the boat to my truck and head south to Florida.

Has to be the best way to winterize

[tcbass]

Hi everyone,

We work for Gold Eagle Co (makers of STA-BIL®) and wanted to help clear up some confusion. The comments about keeping the fuel system full are correct. The best practice when storing equipment is to fill the tank about 95% full, add a high quality fuel stabilizer, and run the engine for a few minutes to ensure the entire fuel system is treated. It is almost impossible to completely drain the tank. Even the smallest amounts of gas will gum up and can clog parts of the fuel system. Also, the more open space you leave in the tank the more susceptible the metal components of the fuel system are to rust & corrosion from condensation.

Please feel free to reach out if you have any questions.

Have a great day!

Thanks for your input! Nice to hear it from a maker of the product.

[GoldEagle]

Thanks for your input! Nice to hear it from a maker of the product.

No problem!  Happy to help with any fuel related questions you may have.

 

Have a great day!

[desmobob]

My outboard is a fuel injected four-stroke.  I fill the fuel tank to the top with a double dose of Startron added and run the engine with the muffs on to make sure the double-treated fuel gets into the engine.  After a L-O-N-G Adirondack winter, she fires up with a touch of the key and runs fine on the full tank of five- or six-months-old gasoline.

 

Tight lines,

Bob

[zachvu]

Draining the tank is definitely not the way to go.  Fill the tank to the top and add stabil.  Not having any dead air space will prevent condensation from being introduced to the tank, and will help prevent fuel breadown and water introduction.  

 

This info comes from textbooks when I was taking small engine mechanics a few years ago.

[zachb34]

I attach the boat to my truck and head south to Florida.

Has to be the best way to winterize

I think that's the second best way to winterize. I like my method of already living in florida year round.

[GoldEagle]

Draining the tank is definitely not the way to go.  Fill the tank to the top and add stabil.  Not having any dead air space will prevent condensation from being introduced to the tank, and will help prevent fuel breadown and water introduction.  

 

This info comes from textbooks when I was taking small engine mechanics a few years ago.

100% correct.  Especially about using STA-BIL®....  

[CWB]

Try Lucas Safeguard ethanol fuel conditioner. I use it regularly during the year and put in a little extra before storing. I like to keep at least a quarter tank full at all times. Even winter. Going on 13 years old an fires right up every spring. Of course it's a Yamaha though.

[tcbass]

Try Lucas Safeguard ethanol fuel conditioner. I use it regularly during the year and put in a little extra before storing. I like to keep at least a quarter tank full at all times. Even winter. Going on 13 years old an fires right up every spring. Of course it's a Yamaha though.

That's a fuel stabilizer?