All Weed Eater brand two-cycle gas trimmers use a 40:1 ratio of gas to oil. That's equal to 3.2 ounces of oil to 1 gallon of regular gas. The gas should be 87 octane with no more than 10 percent alcohol. The oil must be formulated for two-cycle engines.

Does a 4 Cycle Weed Eater need oil?

Four-cycle trimmers don't require you to mix the gas and oil. Simply fill the fuel tank with gas, and fill the oil tank with four-cycle oil. Because four-cycle engines use four strokes during combustion, they tend to run more efficiently and quietly.

How do you put oil in a Weed Eater?

Place the trimmer on a raised flat surface such as a workbench, with the trimmer head hanging over the edge. Pour 3/8 cup of SAE 30 SF motor oil into the oil fill hole. Insert a funnel into the oil fill hole, if necessary, to help pour the oil without spilling it on the engine.