The pull cord on push lawn mowers is made of rope. Over time heat from the lawn mower engine and other elements cause the rope to weaken and break. Replacing the pull cord takes about a half hour to perform if you have the proper tools and the right length of replacement starter cord. Generally you can find the replacement for the starter pull cord at most hardware and home stores.
Remove the spark plug wire from the end of the spark plug. Typically the spark plug is located on the side of the engine that faces the push handles. The spark plug wire is a heavy rubber-coated wire that fits over the sparkplug.
Use either the 7/16-inch or the ½-inch end wrench to remove the three bolts that hold the pull starter cover to the engine. In most applications, two bolts are located on either side of the pull starter housing. The third bolt is located just above the spark plug. Various engines have different size bolts to hold the cover onto the engine.
Fit the end wrench over the bolt head. Turn the wrench in a counterclockwise direction to loosen. Remove the bolts with your fingers.
Remove the starter housing from the engine by lifting upwards. Set the housing on a flat surface, upside down.
Observe the pulley that holds the starter rope. A strong internal spring is mounted inside the pulley. Wind the pulley in a clockwise direction until it will no longer turn.
Back the pulley off until the hole in the pulley aligns with the rope hole in the top of the starter housing. Hold the pulley in place by applying the hand spring clamp to both the pulley and the top side of the starter housing.
Feed the end of the replacement pull cord through the starter housing hole first. Manipulate the end of the rope through the hole in the pulley. Use the needle nose pliers to grab the end of the rope. Pull the end of the rope through the pulley hole.
Pull the rope so about 6 inches of the rope extends past the pulley hole. Tie a knot in the end of the rope. Pull the rope back so the knot rests snuggly against the inside of the pulley and the hole.
Keep tension on the pull rope from the handle end. Release the hand spring clamp. Slowly feed the rope into the spring tension pulley. Allow the spring tension to recoil the rope inside the pulley.
Replace the starting housing cover back onto the engine in the reverse order of removal. Place the spark plug wire back onto the spark plug.