Good question, Paul, and thanks for the note!

Sea Foam is not a replacement for oil in 2-stroke fuel. Use a normal oil at the recommended ratio, and add Sea Foam in addition for cleaning and stabilization. Keep doing what you’ve been doing in your outboard.

Perhaps “In 2-stroke pre-mix” would be a better way to word it on the can. Thanks for the question!

Thanks for the question, Mike. Sea Foam Motor Treatment is safe and effective in your Waverunner’s oil and gas. Marine PRO would work great for both as well.

I’ll answer in general in case others with PWC’s have a similar question:

In a 4-stroke: Add 1 ounce of Sea Foam per quart of oil. Then, run it for at least one hour, and change the oil. That gives the Sea Foam enough time to circulate and clean.

In an older oil-injected 2-stroke, add the Sea Foam at any time.

Hope this helps!

Yes, Sea Foam Motor Treatment (or Marine PRO) would work great in an outboard’s oil crankcase. It will clean and prevent oil residues and deposits from accumulating.

In a 4-stroke outboard: Add 1 ounce of Sea Foam per quart of oil in your outboard’s crankcase. Then, run it for at least one hour, and change the oil. That gives the Sea Foam enough time to circulate and clean.

In an oil-injected 2-stroke, add the Sea Foam at any time.

Hope this helps!

Great question, Sean. Marine PRO will stabilize fuel no matter where it is, as long as that fuel has been treated. It’ll stabilize for up to 2 years. Here’s the important part: make sure you add Marine PRO a while before you store your boat and run it long enough to draw the treated fuel through the fuel system.

It’s okay to add more than 1 oz per gallon as well – adding a full 20 oz can to a low tank of fuel (2-3 gallons) and then running it hard for a while is a great way to clean things up before you put it away for the year.

Sea Foam Marine PRO is safe and effective in your Mercruiser. Marine PRO works through the fuel system to clean fuel residues and varnish that often cause common marine engine problems (rough idle, loss of power, hard starts). Adding Marine PRO to your fuel is an easy way to overcome or prevent these problems.

I’d start by doing this:

Wait until you have a low tank of fuel (2-4 gallons). Add a full can of Marine PRO to the fuel. Run your boat at least 20 minutes if you can (just don’t run out of gas!), and don’t be afraid to run it hard. Then, refill your fuel tank as normal.

After that, you can add Marine PRO to every tank of fuel as preventative maintenance. Add 1 ounce of Marine PRO per gallon of fuel.