Blades should be check before each operation and sharpen if needed. Minimum twice per every cutting season. It is advised to have spare blades that are ready to use in case currently used blades get damaged, need temporarily replacement. To sharpen the blades you should follow the instructions from the film below.
1. Safely raise front of mower.
2. Hold or block blade from turning. Wear heavy, thick gloves when holding onto cutter blade and always avoid the sharp edge of the blade. Make sure blade is centered on pilot before tightening bolt to 60 ft lbs torque