How to Sharpen and Care for Your Walk-Behind Mower Blade

How to Sharpen and Care for Your Walk-Behind Mower Blade

Periodically inspect the blade adapter for cracks, especially if you strike a foreign object. Replace when necessary. Follow the instructions listed below to assist you in sharpening and caring for your walk-behind mower blade.


Step 1
Disconnect spark plug ignition wire from spark plug. Turn mower onto its side, making sure that the air filter and the carburetor are facing up.

Step 2
Remove the bolt and the blade bell support which hold the blade and blade adapter to the engine crankshaft.

Step 3
Remove the blade and adapter from the crankshaft.

Step 4
The blade can be sharpened with a file or on a grinding wheel. Do not attempt to sharpen the blade while it is still on the mower. When sharpening the blade, follow the original angle and grind. Grind each cutting edge equally to keep the blade balanced.

Step 5
To test for balance, remove blade and balance on a round shaft screwdriver. Remove metal from the heavy side until it balances evenly. 

Step 6
Lubricate the engine crankshaft and inner surface of the blade adapter with light oil. Slide the blade adapter onto the engine crankshaft.

Step 7
Place the blade on the adapter such that the side of the blade marked "Bottom" (or with part number) faces the ground when the mower is in the operating position. Make sure that the blade is aligned and seated on the blade adapter flanges.

Step 8
Place blade bell support on the blade. Align notches on the blade bell support with small holes in the blade.

Step 9
Replace hex bolt and tighten hex bolt to torque recommended in your operator's manual. To ensure safe operation of your mower, periodically check the blade bolt for correct torque.