The carburetor might be clogged. A clogged carburetor is often caused by leaving fuel in the edger for a long period of time. Over time, some of the ingredients in the fuel will evaporate, leaving behind a thicker, stickier substance. This sticky fuel can clog up the carburetor and cause the engine to stall or run roughly. If the carburetor is clogged, try cleaning it with carburetor cleaner. If cleaning the carburetor isn’t effective, rebuild or replace the entire carburetor.
The spark arrestor is a small screen that prevents the engine from emitting sparks. Over time, the spark arrestor can become clogged with soot. If the spark arrestor is clogged, the edger may run roughly. To unclog the spark arrestor, remove it and clean it with a wire brush. You can also replace the spark arrestor.