Mercury 8M0047931 Quickleen Engine And Fuel System Cleaner - 12 ozMercury Quickleen is an excellent way to remove carbon deposits throughout the boating season. Keep your carburetors, injectors, valves, pistons, and cylinders working smooth for optimal performance. Help prevent engine knocking, piston seize-up, and extend your spark plug life with this engine system cleaner.Features 12oz bottle; 1 ounce treats 5 gallons; Safe for catalyzed engines; Effectively removes carbon deposits from fuel system and internal engine parts; Protects against engine knocking and piston seizure; Safe for all gasoline-powered 2-stroke and 4-stroke engines, including catalyzed engines; This product does not contain fuel stabilizers. It is for use in all 2 and 4 cycle carbureted and fuel injected gasoline engines.