Add two-cycle oil at the ratio recommended by the manufacturer to unleaded gasoline that has a minimum octane rating of 87, seal the container and mix thoroughly. Remix the fuel before each fueling.
- Select the right octane gasoline
Use 87-octane, regular unleaded whenever possible. If ethanol mix gasoline is the only fuel available, limit the ethanol to 10 percent. Empty the fuel tank on the machine after use when using an ethanol mix to prevent corrosion due to the acidity of the alcohol.
- Determine the correct fuel to oil ratio
As of 2014, all Weedeater products require a 40-to-1 oil ratio. Obtain the correct ratio using 1 gallon of gasoline and 3.2 ounces of two-cycle engine oil. If using premeasured containers of two-cycle oil, read the container label before mixing to ensure it meets the required ratio. Other manufacturers use different fuel ratios for their weed trimmers. Briggs and Stratton two-cycle engines commonly require either a 50-to-1 ratio or a 32-to-1 ratio. Refer to the owner's manual to determine the correct amount of oil for the machine you are using.
- Mix the fuel
Use a fuel can with a leak-proof lid for mixing and storing fuel. Pour the oil into the gasoline and close the lid. Shake the thoroughly to mix the fuel. Over time the fuel and oil separate, so manufacturers recommend shaking the fuel container before each use.