1 Prevent accidental starting
Drain or close off fuel, remove the spark plug cap or battery, and wait for the engine to cool. Position the mower as instructed so fuel and oil do not enter the filter or cylinder.
2 Mark and remove the blade
Clean the underside with gloves, mark the side of the blade facing the deck, and block the blade with a wooden block. Unscrew the bolt with the proper wrench and keep the washer order.
3 Inspect the blade before sharpening
Replace a blade with cracks, deep dents, a bent body, or worn wings. Do not try to repair a safety-critical rotating part by welding or heating.
4 Sharpen both sides at the same angle
Clamp the blade in a vise and follow the existing angle, removing a little material with strokes from the center toward the tip. Keep the grinder moving and do not overheat the edge until it turns blue.
? Tip: The edge does not need to be razor-thin; a slightly blunt finishing edge is more resistant to small stones and keeps its shape longer.
5 Balance and reinstall the blade
Place the blade on a balancer; the heavier side will drop, so remove a little more material from that side. Reinstall the blade in the marked direction and tighten the bolt to the torque from the service manual.
⚠ Warning: Do not use the mower with an unbalanced, cracked, or wrongly oriented blade. Vibrations can damage the spindle and eject parts at high speed.