Things You'll Need
Oil catch container
SAE 30 SF
The Craftsman 4-cycle weed-eating trimmer requires regular maintenance much like any other piece of yard equipment. Regular tuneups keep the trimmer operating at peak efficiency, while regular oil changes keep moving parts in the engine lubricated properly. Changing the oil in a 4-cycle weed eater is much like any other type of gasoline-powered trimmer. Bottles of oil specifically for trimmers are available at home improvement centers. If you cannot find the small bottles, purchase a standard size bottle and measure out the quantity necessary for the engine.
Pull the spark plug wire off the spark plug. Find the oil fill cap on the rear of the weed eater. Wipe down the cap and surrounding area to keep dirt and grime from accidentally falling into the crankcase while changing oil.
Twist the oil fill cap counterclockwise with your fingers and remove it from the trimmer. If the oil fill cap is too difficult to turn by hand, insert the shank of a screwdriver between the two raised portions of the cap. Use the screwdriver as a handle to turn the cap counterclockwise until it's loose enough to turn by hand.
Pick up the weed eater and position the open oil fill hole over an oil catch container. Hold the trimmer upside down with the open oil fill hole pointing toward the container. Allow the oil to drain completely. Once the oil drains, hold the trimmer upright and wipe excess oil from around the oil fill hole, using the rag.
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.
Check the oil level, which should be at the lowest thread on the inside of the oil fill hole. Add oil, if necessary. Twist the oil fill cap clockwise into the oil fill hole until it's tight.
If the trimmer has not been used recently, start the engine and allow it to warm up. Once the engine is warm, turn it off. This helps to remove impurities. Craftsman recommends changing the oil after the first 10 hours of operation and once every 25 hours of operation after that.