Remember one thing about Seafoam- It's more of a Cleaner- NOT a fuel-stabilizer! Do not use it for long-term storage. It has alcohol in it and this just adds more fuel to the fire! With the increasing amounts of Ethanol in our higher-octane fuels Seafoam does squat to combat Ethanol. All your doing is adding more Alcohol to the Alcohol in the Ethanol/ Blended fuels. Not good! Look up the MSDS- Sheets for Seafoam and you shall see. If I may suggest- using Stabil- Marine Fuel Stabilizer for all your marine engines and especially for Long-Term storage. Hope this helps.