The mower deck belt powers the spinning blades that cut grass and weeds. Over time, it can become worn. Simplicity and other riding lawnmower manufacturers recommend checking the mower deck belt annually to ensure it is not cracked or frayed. If the belt needs to be replaced, it can be done with no tools within about 30 minutes. Replacement deck belts can be purchased at Simplicity mower dealers or retailers that sell lawnmowers and other power equipment. The mowing deck does not have to be removed to accomplish this task.
Place the mower on a flat surface. Remove the ignition key and detach the spark plug wire to ensure the unit doesn't accidentally start while you are working on it. Place the mowing deck in its lowest cutting position.
Pull the idler arm on the right side of the mowing deck toward you to release tension on the deck belt. Remove the belt from the idler pulley, which is the smaller pulley located behind the idler arm.
Remove the old belt from the center pulley, which is located in the middle of the deck. Remove the belt from the larger idler pulley, which is in front of the idler arm. Remove the belt from the PTO pulley, which is toward the rear of the mowing deck under the engine.
Install the new belt in the reverse order in which the old belt was removed. Check to make sure the belt is in the pulley grooves.
Raise the mower deck to its resting position. Attach the spark plug wire.
Wear sturdy gloves when working on the mower.