Your hedge trimmer should have been fitted with a pull cord that helps you to turn the machine on; it turns a flywheel that, when it spins fast enough, connects with the ignition module and sends an electric charge up to the spark plug. The pull cord should recoil once you let it go. Occasionally, however, your cord will not recoil as it is supposed to – why is this?
Recoil spring problems
The most common reason for the cord refusing to rewind is a broken or worn out recoil spring. This tiny spring hooks onto the pulley and is stretched out when you pull the cord; when you let go the spring is meant to snap back to its original position. Pulling too hard, wrapping the cord around your hand or pulling it in the wrong direction can all cause the spring to be damaged, which will require it to be replaced.
The pulley, which the recoil spring connects to, is comprised of plastic. This means that it can break if you pull on the cord too hard, wrap it around your hand or pull it in the wrong direction. This pulley also sits on a metal starter post, which needs to be properly lubricated with engine grease to ensure that it spins properly. All of these problems will require the pulley to be replaced, as it cannot be fixed.
Sometimes the pull cord itself may experience issues that prevent it from rewinding, such as its outer layer becoming covered in dirt, pitch, sap or another sticky substance. Occasionally, the cord is known to fray or develop a knot at the base, which can cause it to get stuck in the engine of the hedge trimmer and refuse to rewind. The best way to avoid these problems or to rectify them is to replace the cord on a bi-seasonal basis.
If you are unable to rectify the problem that your hedge trimmer’s pull cord is experiencing using one of the tips above, you might find that the system is facing another problem altogether. The locking key, which connects the flywheel to the crankshaft, may have become bent or the seals on either side of the crankshaft could have worn out.