One of the most common repairs on a push lawn mower is replacing the starter cord. Most push mower use a Briggs & Stratton or Tecumseh engine. Both engines use the starter cord in the same manner. Replacing a pull cord on a Briggs & Stratton lawn mower requires removing the starter cover. Nylon replacement rope is available at most home improvement centers.
Pull the sparkplug wire off the top of the sparkplug with your fingers. Locate and remove the three bolts that secure the starter cover to the top of the engine with a socket wrench. The cover is the portion that houses the starter rope.
Lift the starter cover off the engine and place it upside-down on a flat surface. Grasp the knot from the end of the remaining rope with pliers, and pull the rope out of the plastic pulley. The plastic pulley is the part the rope winds around and the knotted end of the rope should be facing you.
Cut 10 feet of rope from the nylon roll with a pair of household scissors or a utility knife. Rotate the rope pulley counterclockwise with your finger until it stops. This winds the recoil spring under the pulley. Hold the pulley in place with your hand, and clamp the pulley secure to the housing with a C-clamp or a pair of vise grips. Clamp just enough to hold the wound pulley but not enough to bend the starter cover.
Thread one end of the rope through the hole on the outside of the starter cover and into the hole in the pulley. Pull the rope through the hole in the pulley enough that you can tie a knot in the end of it. Tie the knot into the end of the rope and pull the rope from outside the starter cover to seat the knot against the pulley.
Hold the starter cover while you hold the rope on the outside of the starter cover; have a friend help. Slowly release the C-clamp or vise grips and slowly allow the recoil spring to turn the pulley and wind the rope until it stops.
Place the starter cover over the top of the engine and secure with the retaining bolts. Thread the opposite end of the rope through the loop in the mower handle. Insert the rope through the center of the rope handle and on the rope slightly. Allow the rope handle to rest on the lawn mower handle.
Tie a knot in the rope to secure the rope handle. Cut off the excess rope with scissors or a utility knife.