McCulloch manufactures the Eager Beaver line of weed trimmers. All McCulloch trimmers require a fuel mixture that contains gasoline and two-cycle engine oil. McCulloch recommends using a 40:1 ratio of gasoline and oil for optimal engine performance. The best way to mix the fuel mixture is in a gas can. Two-cycle oil containers usually have measurement markings on the side of the container for quick measuring.
Purchase a 1-gallon gas container specifically to store the fuel mixture for your weed trimmer. You can purchase gas cans at gas stations and home improvement centers. Write on the gas can in permanent marker, "Trimmer Fuel" or something similar. This fuel is for your trimmer only.
Fill the gas can with 1 gallon of gasoline. Pour 3.2 ounces of 2-cycle engine oil into the gas can.
Put the gas can lid on and shake the gas can vigorously to mix the oil with the gasoline. Fill your trimmer fuel tank with this fuel mixture only.