The string trimmer small engine often has a separate model number. Use the small engine model number for a complete list of symptoms and parts. Watch our model # lookup video for help finding the model number.
The 5 most common part(s) or condition(s) which cause the symptom String trimmer won't start are listed below starting with the most likely. Check or test each item and watch any available videos.
RepairClinic Item # 1951816
If the string trimmer won't start, the carburetor might be clogged or have bad fuel in the float bowl. If old fuel was left in the string trimmer for a long time some of the volatile ingredients may have evaporated, leaving a thicker, stickier product that is more like varnish or shellac. This sticky fuel can clog up the small jets and ports in the carburetor and it can be difficult to burn making it hard to start the engine. The only solution is to drain the old fuel from the float bowl and thoroughly clean the carburetor with carburetor cleaner. If that isn't effective, replace the entire carburetor.
RepairClinic Item # 1954371
When the starter rope is pulled and let go the rewind spring is supposed to recoil the rope onto a pulley. If the rewind spring is broken the rope can't be recoiled onto the string trimmer pulley which will prevent it from turning over the engine, and then it is hard to start. Many rewind springs can be replaced but it's sometimes easier to replace the whole recoil starter assembly.
RepairClinic Item # 1951877
If the string trimmer won't start the recoil starter assembly might not be engaging with the crankshaft and turning over the engine. Remove the starter assembly to see if it is functioning properly.
RepairClinic Item # 1953687
When the starter rope is pulled and let go the recoil spring is supposed to recoil the rope onto the recoil starter pulley. If the recoil spring is broken the rope can't be recoiled onto the pulley which will prevent it from turning over the string trimmer engine, and then it does not start. Many recoil springs can be replaced but it's sometimes easier to replace the whole recoil starter assembly.
RepairClinic Item # 1953778
If the string trimmer won't start the air filter might be clogged. Remove the air filter and replace with the correct filter.