I have 2 similar questions: I have a motorcycle that sat for about a year and now won’t start. I believe the gas in the carbs tarnished. I also bought a boat with a 2-stroke that sat for over a year, I believe the same problem. Before I tear down and rebuild the carbs would Sea Foam actually get in the carbs and clean them out?
Great questions, Jim. Yes, Sea Foam in fuel will remove the suspended fuel gum and varnish that causes clogged carburetor jets and other sticky restrictions. Because a carburetor is vented to the atmosphere, light gasoline ignition vapor will evaporate and cause the fuel to oxidize and become heavy/thicker and less volatile. When added to fuel, Sea Foam liquefies the heavier fuel varnish back into the liquid fuel phase, allowing the gas to run cleaner through the carburetor circuits. There is no need to clean a carburetor if you use Sea Foam regularly!
For your motorcycle and outboard you'll need to get Sea Foam into the carburetors to clean – try this: https://seafoamworks.com/uploads/public/resource-library/2022/07/HOW2_GummedUp-Carb.pdf