Good question, Robert. Here’s what I’d recommend:

Simply add Sea Foam Motor Treatment to the fuel, and run it for about 15 minutes. That will draw the treated fuel through all parts of the fuel system so it’s protected during storage. A high concentration (4-6 oz of Sea Foam per gallon) will do a great job cleaning the fuel system when you’re running it, as well as stabilize the fuel for storage.

It’s up to you whether you store it with a full or partial tank.

Here’s a link with detailed instructions on storage if you’d like more info:

https://seafoamworks.com/uploads/public/resource-library/2022/07/HOW2_Small-Engine-Storage.pdf

Hope that helps!

Great question, Grey. Yes, Sea Foam Motor Treatment will also stabilize diesel fuel for off-season storage or bulk fuel storage. Use 1 ounce of Sea Foam per gallon of fresh diesel fuel.

[Unrelated to fuel stabilization, note that Sea Foam Motor Treatment is not a biocide, though, so get a specialized product for that if it’s a concern].

Good question, Ted. Using Sea Foam in every tank of gas in a lawnmower is actually a great way to keep it running well. Unlike cars and trucks (which get driven all the time), a lawn mower might sit for a few weeks or months in between use. That’s when fuel begins to degrade and gum and varnish begins to form in the fuel system. Sea Foam prevents fuel from degrading and cleans out any gum or varnish that forms (which is a very common cause of mower engine problems and poor performance). It’s cheap insurance that’ll help keep your mower running well and prevent problems.

Add 1 ounce of Sea Foam per gallon of fuel.

Hi Ashley,

Sea Foam certainly can help! Over time, varnish and residues will build up in a fuel system if it has been sitting a while. Sea Foam works to clean the varnish and residues so the engine can start and run strong.

Here’s what I would do: Remove as much old fuel as you can knowing that any varnish will sit at the bottom of the tank. [Don’t worry about the varnish…Sea Foam will liquefy the varnish.] Add a can of Sea Foam High Mileage to the tank, followed by a gallon of fresh fuel. [If you can’t remove some of the old gas, just add the Sea Foam and new gas to what’s there.] Start and run the engine for 10 minutes draw the Sea Foam through the carburetor circuits. Shut off the engine and let the ATV sit overnight or longer. 2 to 3 days is better. After the long cleaning soak, add another gallon of fresh gas and run the engine for 5 to 8 minutes to heat up. Then take the ATV for a short spin to create more upper engine heat and compression. Much of the Sea Foam will remain in the tank and continue to clean as you go. At that point the fuel system and fuel passageways should be very clean!

If the engine isn’t starting at the moment, follow the directions above with these slight differences:

• Drain the fuel in the carburetor as well (it’s usually a small screw)
• Instead of starting the engine after adding the Sea Foam, simply crank it a few times to draw the Sea Foam into the carburetor

If the engine isn’t starting because of gum or varnish in the fuel system, this will help clean it up and get it running again.

Hope that helps and let us know if there’s anything else!

As long as the cap is on tight and the liquid is clear, Sea Foam Motor Treatment will stay good for dozens of years. Go ahead and use it.