Thanks for the question, James. Sea Foam won’t damage your E-TEC. It’s made with petroleum cleaning and lubricating ingredients that can’t harm engine parts or components. It’s okay to use in your 2018 E-TEC 25 hp. For your outboard, I’d also consider Marine PRO.

For regular preventative maintenance, use about 1 oz per gallon of fuel in every tank of fuel. If you’re trying to clean fuel gum and varnish from the fuel system, use a higher concentration. I’d wait until the tank is low, add a full can of Marine PRO, and run the engine for at least 20 minutes before adding more fuel. You can use up to a 1:2 ratio of Sea Foam to fuel (though you don’t need that much – a can of Sea Foam in a gallon of fuel would work just fine).

Hope that helps and let me know if you have any other questions!
Best,
Conner
Sea Foam

Thanks for the question, Kay.

No, Sea Foam does not remove ethanol.

What Sea Foam does do is help stabilize fuel and prevent the formation of fuel gum and varnish as gasoline ages. It’ll also add protective lubricity and help protect parts from corrosion. Sea Foam is safe to use with ethanol-blended gasoline, including common E10 fuel.

If you’re storing an engine or equipment, add Sea Foam to fresh gasoline before storage and run the engine long enough to circulate the treated fuel throughout the fuel system.

Hi Les,

Thanks for the question! You can use Sea Foam Motor Treatment in your diesel tractor. Just follow the directions on the can. Let me know if you have any other questions – happy to help!

Hey Frank,

Good question! If the problem is being caused by fuel gum or varnish, Sea Foam will help clean it up. Here’s what I’d do. Since your gasoline is fresh, you don’t need to throw it away. Drain most of it back into an approved fuel container. I’d actually recommend a bit stronger concentration, up to a 1:2 ratio (1 part Sea Foam to 2 parts gasoline…which is 8 oz (half a can) of Sea Foam in a pint of gas).

Start by draining the carburetor. Then, try starting or cranking the engine several times to draw the mixture into the carburetor. Getting the treated fuel into the carburetor is the main goal. Then let it soak overnight. The high concentration gives Sea Foam a much better chance to liquefy the gum and varnish that may be blocking the carburetor’s small passages.

If it still won’t start after the treatment, the problem may be something other than gum and varnish.

• For regular maintenance: Add about 1 oz per gallon, so roughly 17 oz (500 mL) for a full tank.
• For cleaning: Rather than treating all 65 liters, I’d wait until the tank is 1/4 full or less, then add a full 16 oz (473 mL) can of Sea Foam Motor Treatment. Drive at least 10–20 miles before refueling.