Winterizing - Gas Tank Full??? "or" Empty"

[Debbie Bakalich]

Winterizing - Gas tank full?? or gas tank empty??

I purchased my first boat in July, a Maxum 2800 SCR and to say the least I am a work in progress. I am non-mechanical but read the manuals and I am trying to understand everything I can about my boat and proper maintenance. Now that it is time to winterize I get some people telling me because of the ethanol in gas to fill the gas tank up to minimize condensation.....the other 1/2 says run it to empty, both say put stabilizer in it either way...etc. I really need some direction on this and is there a tank that holds condensation flow from gas tank that I need to pay attention too? And while on the ethanol topic.....(I read too much), is there a conditioner that I need to put in the gas each time I fill up?

[seapuppy]

fill the tank up with fuel...put stabilizer in the tank before adding gas....this is recommended by the manufacturer....reason is that the empty tank will absorb more water and will also evaporate faster when it has a lower level in the tank..thus leaving nasty stuff in the tank...
so...for this sized boat...fill it with stabilizer...if you had a little 16 ftr with a carry on tank..I'd say empty the tank.....
no conditioner is really needed if your burning the gas off often enough..for long term storage...you need to use something to keep the alchohol from absorbing water....another might wanna do item is to install a water seperator type fuel filter inline so that it will separate the water from the fuel...you can pull the bottom cap off ..drain the water off...and put it back on....

SP

[ss3964spd]

Hi ya Debbie,

There are a LOT of opinions on how best to handle this, but I will tell you what I did last season and you can decide.

My tub holds 70 gallons. After reading the instructions I purchased 2 bottles (1 bottle of any brand will treat only X number of gallons) of Sta-Bil Marine Formula.

I took the boat out onto the South River one last time last October and filled the tank. I poured both bottles of Sta-Bil into the tank and then motored around for a couple of hours, which insured the fuel treatment was completely mixed in with the gas AND that the now treated gas had made it into the engine. By the time I took the boat out of the water there was probably 60 gallons of treated gas still in the tank.

Winterized the rest of the boat and then it sat all winter.

When I splashed the boat this Spring all I did was start the engine. It ran perfectly, no gas related issues whatsoever.

I do not believe you need to use gas treatments continuously. My "honey do" pick up truck sits in my driveway, unused, for months sometimes and has never had gas related problems. My old classic convertible hibernates in the garage all winter long and has also never had a gas related problem.

So, my opinion; add the correct amount of treatment, run the boat long enough to ensure it is mixed and gets into the engine, and don't worry about it.

Finally, I doubt your boat has a separate holding tank but it probably does have gas/water separator(s). If you are having the a mechanic winterize the boat do consider having the separators changed/replaced before you splash the boat again next spring.

Regards,

Dan

[Debbie Bakalich]

Thank you Dan. It appears that the recommendation is to store it with a full tank of gas and stabilizer. I will look into the Sta-Bil Marine Formula. I do not know if I have a gas/water separator but will be looking it up this weekend when I head to the boat. Thank you for replying! Debbie

[Debbie Bakalich]

Thank you! I will fill up the tank and put stabilizer in it. If I do not have a water separator in the boat is that something that can wait until spring or needs to be done now?

[seapuppy]

Originally Posted by Debbie Bakalich

Thank you! I will fill up the tank and put stabilizer in it. If I do not have a water separator in the boat is that something that can wait until spring or needs to be done now?

not necessarily needed at all..but it's definitely something I'd do to it next spring...

SP

[shrew]

This is probably the most widely discussed and disputed topic when it comes to winterization. Variations in regional climate compound the discussion. I look at this like an old school/new school debate though at this point I think it is so old even that doesn't apply. I can tell you this, despite what Mercruiser says, I leave it full. There are up and down sides to either. Leaving the tank empty significantly reduces phase seperation (fuel going old), however it causes a condition where condensation builds on the inside of the tank walls and then 'rains' into the tank. You can potentially end up with water at the bottom of the empty tank.

Take a look at what Mercruiser officially says:

http://www.mercurymarine.com/service...=winterization

What should be done when storing boats with ethanol-blended fuels for extended periods?

Follow the instructions for normal storage preparation found in the Operation, Maintenance & Warranty manual. When preparing to store a boat for extended periods of two months or more, it is best to completely remove all fuel from the tank. If it is difficult or not possible to remove the fuel, maintaining a full tank of fuel with a fuel stabilizer added to provide fuel stability and corrosion protection is recommended. It is best to add the stabilizer and fuel treatment to the tank at the recommended dosage, run the engine for 10 minutes to allow the system to be cleaned, shut off the fuel valve to interrupt the fuel supply and allow the engine to run until it stops, and top off the tank until it’s full to reduce the amount of exchange with the air that might bring in condensation. Do not cap the tank vent and do not fill with fuel to the point of overflowing. Some extra space should be maintained in the tank to allow for expansion and contraction of the fuel with temperature changes. A partially full tank is not recommended because the void space above the fuel allows air movement that can bring in water through condensation as the air temperature moves up and down. This condensation could potentially become a problem.
Mercury Marine Fuel System Treatment & Stabilizer can help maintain fuel systems in storage. It contains oxidation inhibitors to reduce oxidation and gum formation, metal-chelating agents to protect metal components from corrosion, water-absorbing agents to reduce the presence of free water, and dispersants to help suspend and disperse debris. When placing the boat back in service, be sure to reopen the fuel valve to the engine.



Note that while they do recommend leaving it empty, they also acknowledge that it CAN be left full as well. My opinion (Hey, I'm just another guy with a computer, internet connection and opinion on the internet) is to leave it FULL and do the following:

1) Add Stabilizer designed for maring environment and ethenol:

http://www.westmarine.com/webapp/wcs...classNum=10437

2) I also put in some Stay and Store as well (1 of the following):

http://www.westmarine.com/webapp/wcs...classNum=10437

http://www.boatfix.com/bykeywordmerc...&submit=Search

http://www.westmarine.com/webapp/wcs...classNum=10437

3) Startron: This will handle any water which does develop in the tank during storage

http://www.westmarine.com/webapp/wcs...classNum=10437


It is ok to put in all three. Then top off the tank. Running it long enough to push ful through the pump and engine is a good idea. Your going to put the outdrive on muffs to flush the engine anyway.

Don't forget to drain the engine.