The Tecumseh 3.5 HP vertical shaft engine is used on a wide varieties of lawnmower makes in models. Over time, the pull starter rope may become frayed and break due to chaffing or over exposure to the elements. The average person can accomplish replacing a pull start rope for this Tecumseh engine as long as the proper tools are available. When the old pull starter is removed, replace it with the recommended factory made rope or simply take the old rope to a hardware store and find a suitable replacement.
Remove the recoil starter housing from the engine. On some models, the recoil cover bolts are located on the raised cylindrical portion of the pull starting unit for easy removal. Older models may require you to completely remove the engine cover housing via the three 7/16-inch bolts: two bolts near the spark plug and one on the rounded portion of the housing.
Turn the recoil starter over to expose the pull start mechanism and remove the old rope from the recoil mechanism. Some pull start ropes may be held on to the pulley by a knot or a staple. You will need to remove the staple or knot in order to free the rope from the pulley.
Tension the recoil assembly pulley by hand as far as it will go and then line up the rope hole on the pulley to the rope hole on the housing. Secure the pulley to the housing with a C-clamp to keep it in position.
Route the new rope through the housing opening and through the rope hole opening on the recoil pulley. Tie a knot and use a lighter to melt the plastic coating on the rope and seal the knot. Pull on the rope to lodge the knot into the pulley hole.
Route the other end of the rope through the pull start handle and then tie a knot at the end to secure the handle and use the lighter to seal the knot. Release the C-clamp to allow the rope to recoil into the assembly. Reinstall the recoil housing assembly on the engine.