Stihl makes several models of gas-powered string trimmers acceptable for home yard maintenance. All the trimmers come equipped with a recoil starter unit which lets you start the machine by pulling the starter cord. Unusual sounds that happen when you pull the starter cord or that emanate from the starter unit during cutting signal that you may need to make a fix.
Starter Cord Symptoms
If you have ever powered up a gas-powered string trimmer, you realize pulling the starter cord makes some noise. A whipping noise that takes place when you pull the cord is perfectly normal. Squealing, rattling or grinding sounds signify a possible internal issue in the starter unit. Fortunately, there are a limited number of parts in the starter recoil, making it easy for you to replace or repair.
Removing the Starter Unit
To access the starter recoil unit, then remove it from the machine and then analyze the internal parts. To remove the starter from the Stihl trimmer, remove the spark plug wire from the spark plug and then lay the machine on a level work surface. Remove the screws which hold the starter unit set up and pull the starter unit from the machine. All the parts of the recoil starter are within the unit you have just removed.
Once you’ve accessed the interior of the recoil starter unit, then you may see what is causing the noise. A frayed, ripped or broken starter string may be in the bottom of the issue. It might also be a broken or bent spring, or a crack or break in the plastic pulley that the starter string winds around. If nothing seems to be incorrect and the string pulls and recoils with no issue, reattach the starter unit into the machine and make sure all screws are tightened properly. Begin the machine to see if the noise has resolved.
Replacing the Starter Assembly
Once you have the starter assembly off the machine, replacing it with a fresh one isn’t a issue. Stihl sells whole starter unit assemblies which make it pointless to replace individual interior elements of the starter unit. Eliminate the newest starter recoil out of the packaging; align it properly on the face of the string trimmer, and attach it with the screws which held the old starter assembly set. Pull the string to start the trimmer and make sure it’s noise free.