Quicksilver Quickleen is used to quickly and thoroughly remove carbon deposits from carburetors and injectors, intake valves, spark plugs, piston crowns, and cylinder heads. Use this lube to prevent engine knocking and piston seize-up, plus extend the life of your spark plugs in all 2 and 4-cycle fuel-injected gasoline engines including cars, trucks, motorcycles, ATVs, snowmobiles, marine engines, lawn mowers, and more. Safe for catalyzed engines. Note: This product does not contain fuel stabilizers. 1 oz. will treat 5 gallons of fuel.