Decarbonize your boat’s outboard motor in order to remove harmful carbon deposits from your pistons and cylinders to prevent damage and increase performance! 2 stroke or 4 stroke, this SeaFoam method works for either type of motor.Click to see full answer. Likewise, people ask, can you use seafoam in a 2 stroke outboard? Re: A must read for all 2 stroke outboard owners. Engines run terrible under load with that much Seafoam. It’s just supposed to be a shock treatment to remove carbon. It works best when you spray it directly into you carbs until the engine stalls. Then you let it sit for a while and start it up on regular fuel.One may also ask, how much seafoam do I need for a 2 stroke outboard? 1 pint of Sea Foam mixed with 2 pints of fuel will treat several outboards. Also question is, can you use seafoam in outboard motor? Safe & easy to use in all 2- & 4-stroke gasoline marine engines, inboard & outboard. Also great for all types of personal watercraft (PWC). When added to marine engine fuel, Marine PRO works to clean & lubricate your entire fuel system.Can seafoam hurt your 2 stroke engine?sea-foam is a petroleum product it will not harm any motor.