Weedeaters are small gas- or electric-powered yard maintenance tools used for edging where regular mowers can't go. Gas weedeaters have a small primer bulb that pumps fuel into the carburetor to prime it for starting. Primer bulbs are made of plastic and rubber. After years of pushing, bad weather and neglect, most primer bulbs crack or break. Even with good care this will likely happen. Replacing the primer bulb is simple and won't cost much in time or money.
Remove the air filter cover and the air filter by removing the screw holding it to the engine. This is usually located in the middle of the cover.
Remove the two screws holding the carburetor in place. Lift the carburetor off the engine.
Remove the screws holding the primer bulb casing to the carburetor. Remove the primer bulb. Wipe away excess dirt and oil using a clean rag. Insert a new primer bulb into the casing. Reattach the carburetor and the air filter.