A Weed Eater two-cycle engine requires a mixture of gas and oil in the ratio of 40:1. To obtain this ratio, one gallon of gasoline should be mixed with 3.2 ounces of engine oil.
Weed Eater recommends using regular unleaded 87 octane gasoline and two cycle oil that is made specifically for air cooled engines. Weed Eater engines can, however, run on alcohol blended fuel containing up to 10 percent alcohol. The gas-oil mixture should not be stored for more than 90 days because old fuel mixture can cause the engine not to start. The fuel mixture should also not be left in the machine for more than 30 days to prevent formation of gum deposits that can foul the fuel system.