Pour the contents of a 2.6 fluid ounce of two-cycle engine oil into a spare gas can. Stihl recommends using their Stihl 50:1 two cycle engine oil.
Add 1 gallon of unleaded gasoline to the gas can. Close the gas can top, and shake the fuel mixture vigorously. Adding the oil to the can first helps to ensure it proper mixing.
Wipe the leaf blower filler cap and the area around it with a clean rag. This helps to prevent dirt or debris from falling into the fuel tank when filling.
Twist off the fill cap on the Stihl leaf blower. Shake the spare gas can once more to ensure the fuel is mixed, and pour the fuel mixture into the Stihl leaf blower tank.
Pour until the fuel is one inch below the filler neck. Twist the fill cap clockwise until it stops.