While most major repairs of your Briggs & Stratton lawnmower will require taking it for a full service, there is one common repair that you can do on your own. Because of the wear and tear the pull cord gets, it has a tendency to snap. When it breaks, you will be unable to start the lawnmower and will have to replace the cord. Luckily, replacing the pull cord is an easy task which should take you just a few minutes.
Unscrew the bolts that attach the fuel tank to the back of the mower. Remove the tank from the engine.
Remove the bolts on the starter housing and remove the casing on top of the engine. Locate the pulley in the housing that has the old cord wrapped around it. Remove the old cord from the housing.
Spin the pulley so that is all the way to one side -- the pulley is spring-loaded, so spin it to the "Open" position. Thread one end of the rope through the pulley and tie it off so it is attached to the pulley. Slowly spin the pulley the other direction so the rope coils around it.
Feed the loose end of the rope through the opening of the housing cover. Place the housing back on the mower, and reattach the fuel tank with the bolts.
Feed the rope through the cord guides on the mower handle. Cut it to length, and wrap the end with electrical tape. Feed the rope into the cord handle. Staple the top of the handle with the staple gun, and then push the staple into the handle with the pliers.
You may be tempted to wrap the cord around the pulley while it is in the "closed" position. While this will work, you won't get a good fit for the rope. It's better to feed it through when the pulley is open and then let the pulley coil it.
Remember to remove the fuel tank. Not only will it be easier to get to the housing, petrol is volatile and can cause explosions if not cared for properly.