Help Blog

When you want your lawn to look its best, a sharp mower blade is your best friend. Even if you're not planning to service your blade, you should still periodically inspect the blade adapter for nicks, cracks, and rust. If you do notice this type of damage, use a mower blade sharpener to grind a new edge. If the blade is badly bent and you can no longer sharpen it, the entire blade will need to be replaced. Below are instructions for more typical blade maintenance and service. 

1. Remember your safety. Disconnect the spark plug wire. Place the mower on its side with air filter and carburetor facing up. 

2. Now you can begin to remove the mower blade - you should never try to sharpen the blade while it is still on the mower. Wearing work gloves to complete maintenance is highly advised. Remove the blade ball support and hex bolt that holds the blade and blade adapter to the engine crankshaft. Remove the blade and adapter from the crankshaft. Secure the blade in a vice. 

3. You can use a mower blade sharpener or file on a grinding wheel to sharpen the blade. When sharpening, follow the blade's original angle and grind. Grind each cutting edge equally to keep the blade balanced. 

4. Your blade must be balanced before replacing. Test this by balancing the blade on a round shaft screwdriver; shave the metal from the heavy side until you have an even balance. 

5. Lubricate the inner surface of the blade adapter and the engine crankshaft with light oil, then slide the blade adapter onto the crankshaft. 

6. Make sure that the side of the blade marked "bottom" faces the ground when the mower is turned right side up. The blade should be aligned and seated on the blade adapter flanges. Replace the blade bell support on the blade and align the notches with the small holes in the blade. Now replace and tighten the hex bolt to the recommended torque as advised by your manual. 

7. Turn the mower right side up and reconnect the spark plug. If you hear vibrations or noises when you start the mower, adjust the blade balance as necessary. 

As always, remember to work safely and refer to your owner's manual or a trained specialist for any model specific questions. Need replacement blades, belts, or pulleys? Use our Parts Lookup tool.