Mercury Quickare Fuel Treatment Additive - 92-8M0047320 Great for cleaning up existing deposits in untreated fuel lines, tanks, carburetors, injectors, intake valves, and spark plugs Keeps your fuel fresh for up to three months Can be used in all 2 and 4 cycle carbureted and fuel-injected gasoline engines Use one ounce to treat every 10 gallons of fuel.