A weed eater starter assembly includes the pull cord, starter pulley and spark plug. When you pull the cord, it spins the starter pulley and flywheel, and the spark plug fires to start the engine. Starter pulleys are made of plastic and can bind and break, thus needing replacement. A new starter pulley usually includes a new spring and hub to replace all three parts at once and prevent another of the three from malfunctioning in a short time. Starter pulleys are inexpensive parts and most homeowners can replace them in short time with few tools.
Turn off your weed eater and let the engine cool. Place your weed eater on a flat surface with the starter pull rope facing up. Remove the spark plug wire to prevent accidental starts.
Remove screws around the recoil starter pulley with a screwdriver. Most have four screws on the housing around the starter pull cord. Pull the starter assembly straight up and place it on a flat surface upside down.
Pull out the starter rope, push it through the handle and untie the knot, using needle nose pliers to loosen it. Pull the handle off the rope, and then allow it to rewind slowly into the pulley.
Remove the pulley screw in the center with a flat-head screwdriver. Put on leather gloves, pull off the starter hub and spring, lifting straight up from the pulley. Lift the starter pulley out of the assembly. Pull the loose end of the starter rope out and unwind it from the pulley. Lift the end of the rope with a knot out of the starter pulley channel and pull the rope through by the knot to remove it from the pulley.
Insert the unknotted end of the rope through the new pulley hole on the inside of the channel, pull it through and press the knot inside the channel.
Wind the loose end of the rope onto the pulley counterclockwise. Secure the end of the rope in the V-shaped notch in the pulley. Place the pulley in the assembly and rotate it slightly left and right until it catches on the pulley tab. The pulley slightly drops when it is in place.
Place the new starter hub spring on the center of the pulley and then the new starter hub on the top. Hold the pulley in place and replace the screw in the center, turning it clockwise.
Turn the pulley counterclockwise three to four revolutions to tension the spring. Pull the end of the rope up and out of the notch and feed it through the starter housing from inside to outside.
Pull the rope out and hold it in place with one hand. Insert the end through the starter handle and secure it with an overhand knot. Release the handle and allow the rope to recoil slowly.
Replace the starter housing assembly onto the weed eater, and then insert and tighten the screws clockwise.