Storing the Boat: Fuel and additives

[Paulywood]

What do you guys do with your fuel when you put the boat away for the winter? Some guys fill the tanks up, some empty them out. Do you use Stabil or another additive? If there is a reason for what you do feel free to let the rest of us know. I always used to fill the tank up completely to avoid condensation. Then I added Stabil. Last year I used the new marine Stabil. I was reading an article that stated it might be better to leave the tank low on fuel (less than 1/4 tank) and then fill it up in the spring with new gas. After you run a tank through change the fuel filter and you should have must of the water and crud out of your tank. So that is what I am going to do this year. I also decided to use Seafoam instead of Stabil. I'm hoping it will help clean out the fuel system in the spring.

[anthonyyost]

You should probably fill the gas tanks, this helps prevent condensation from forming. Adding stabil or other type of fuel stabilizer as well as fogging or pouring storage oil into the carb while running will prevent moisture from causing problems.

[Nailer]

According to what I have read, Seafoam is considered to be on of the best all around gas additives.

[flyman013]

I run Sta-Bil and leave the tank full as mentioned above. I don't run the engine completely dry. This way, the seals stay moist and don't tend to dry out in the off season.

[MY2SONS]

I fill both my tanks with gasoline that doesn't contain ethenol (i.e. "marina gas"), and then add Seafoam to stabilize the fuel during storage. I called the manufacturer of my boat and asked what they recommended and he said Seafoam was preferred over Stabil. Port Sheldon Party Store has non-ethenol gas at pump #5 if anyone who lives in this area is interested.

[MY2SONS]

What do you guys do with your fuel when you put the boat away for the winter? Some guys fill the tanks up, some empty them out. Do you use Stabil or another additive? If there is a reason for what you do feel free to let the rest of us know. I always used to fill the tank up completely to avoid condensation. Then I added Stabil. Last year I used the new marine Stabil. I was reading an article that stated it might be better to leave the tank low on fuel (less than 1/4 tank) and then fill it up in the spring with new gas. After you run a tank through change the fuel filter and you should have must of the water and crud out of your tank. So that is what I am going to do this year. I also decided to use Seafoam instead of Stabil. I'm hoping it will help clean out the fuel system in the spring.

The reason some places recommend running the tanks dry is because the fuel that contains ethenol draws moisture and is subject to phase seperation, and half-full tanks would leave a lot of room for condensation to build. Ethenol strips vital lubrication from the cylinder walls, and other metal parts leaving it vulverable to corrosion from the moisture. If you can find gasoline that doesn't contain ethenol fill your tanks to the top, and use Seafoam to stabilize it over the winter. Marina's have non-ethenol gasoline. Fogging the cylinders, and flushing the engine with -100F marine antifreeze will prevent costly repairs if your boat is kept in an unheated garage, or outside.

[flyman013]

Would the SeaFoam or Sta-bil neutralize the ethanol, or would you still be vulnerable to moisture absorbance??

[1mainiac]

I have used both Sat Bil and Seafoam I prefer Seafoam but that is just me. I leave a 1/4 tank in it and fill up and change the water seperator filter after the first tank in the spring. As for condensation there is little to no humidity in the winter IE very little condensation you get more water in your tank due to condensation during the summer than you ever will in winter. However current fuels break down rapidly over time as the additives to boost Octane are not as stabil as the lead componds used before Unleaded gas vehicles. So the last thing I want in the spring is a full tank of old fuel.

[Priority1]

Two thumbs up for Seafoam. I add the Seafoam, then run the engine until it's up to temp, then top off the tank. The reason for running the engine is to get the stabilizer into the fuel pump and carburetor. In the Spring I fill up the boat after every trip. Later in the year I may go two or three trips before fueling. After a long lay up, all the fresh fuel you can add, just can't hurt.

[tangled mess]

i always store with a 1/4 tank of fuel or less and i do not use any adtives i just fill up when it gets in in the spring and then after the first trip i change plugs and filters.

[MY2SONS]

Would the SeaFoam or Sta-bil neutralize the ethanol, or would you still be vulnerable to moisture absorbance??

From what I've been told by my boat manufacturer the stabilizers will prevent the gas from turning to varnish, but it won't "neutralize" the ethenol it will just help by controlling moisure in the fuel. Humidity obviously isn't a problem in the winter, but there's moisture that collects in the fuel tanks at the gas station especially if you buy from a station that doesn't have a lot of fuel volume being sold. Non-ethenol fuel has a lower absorbtion rate then with the ethenol alcohol which draws moisture.

[Nailer]

Port Sheldon Party Store has non-ethanol gas at pump #5 if anyone who lives in this area is interested.

This is great to here. I've read a lot of bad things about the Ethanol in Gas.