All engines develop performance issues over time, whether they're gas, diesel or ethanol. Carbon deposits reduce performance and fuel economy. Water and ethanol corrode key engine parts. Gumout Multi-System Tune-Up is the most advanced treatment for all types of engines, from cars to lawn mowers. It cleans and conditions using premium ingredients, like PEA (polyether-amine), to help maximize performance, fuel economy and engine life. Multi-System Tune-Up can be added in the gas tank, the crankcase or via induction. Directions: Add to fuel: For optimal results, add entire can to the tank. Fill the tank with fuel and run to near empty before refueling. One pint treats 18-21 gallons of all types of gas or diesel fuels. Add to oil: Add one ounce per quart of oil. Immediately start engine and run for 5-10 minutes to mix completely. Vacuum Intake Cleaner: May be used with engine decarbonizing equipment through the vacuum system to clean intake manifold, valves and combustion chamber. Follow recommended mechanical procedures for the equipment. Small 4-cycle engines: Add to gasoline using ¾ to 1 ounce per gallon of fuel. Small 2-cycle engines: Add to gasoline using ¾ to 1 ounce per gallon of fuel. Add 2-cycle oil as recommended by engine manufacturer. Gumout Multi-System Tune-Up does not replace 2-cycle oil.