Mower blades encounter rocks, hard soil and debris when mowing the lawn, which causes damage to the blades. They should be inspected at each mowing session and promptly replaced when rust, nicks or other types of wear are observed. This will keep the lawn looking pristine and your mower running efficiently. Riding mower blades are under the mower deck with most mowers having two or three blades.
Park the mower on a flat surface such as a garage floor or driveway. Place the mower in "Park" and detach the sparkplug from the wire to prevent an accidental start.
Disengage the mower deck, unbolting it from the mower. Remove the drive belt and screws located beside the engine pulley. Slide the deck from under the mower.
Flip the deck upside-down to provide access to the blades. Wedge a block of wood against the mower blades to prevent them from turning during the removal process. Loosen the nut in the center of the mower blade, turning it counterclockwise with a wrench. Remove the nut and lift the blade up the spindle, handling it with care.
Position the new blade over the spindle and slide into place. Secure with the nut, tightening the blade into place.
Turn the deck over onto its wheels and slide under the mower. Reattach the drive belt and screw the deck into place with the removed screws and a screwdriver.
Reattach the sparkplug.