Small Engine Manual

Sharpen or replace a lawn mower blade

A dull blade tears grass instead of cutting it. Sharpen it once a season, and replace it if it is bent, cracked or worn thin.

Step by step

Take the blade off and put it back

Safety Pull the wire off the spark plug before you touch the blade or reach under the deck. Wait for the blade to stop completely first.

Take the blade off and put it back: steps
01Disconnect the spark plug wire first. Then run the tank dry or pump the fuel out.Don't siphon fuel by mouth.
02Tip the mower the right way: air filter side up on Briggs & Stratton engines, muffler side down on Honda GCV170.Tipping the wrong way floods the air filter with oil.
03Wedge a block of wood against the blade and loosen the bolt.Wear heavy gloves.
04Note which way the blade faces, then remove it and its hardware.
05Sharpen the cutting edges with a file or grinder, keeping the original angle. Take the same amount off each end.Never sharpen a cracked or bent blade. Replace it.
06Check the balance on a blade balancer or a nail through the center hole. File the heavy end until it hangs level.An unbalanced blade shakes the engine.
07Refit with the curved ends pointing up toward the deck.
08Torque the bolt to the mower maker's figure.Toro Recycler 22 in.: 60 ft-lb (82 N·m).
09Set the mower upright, reconnect the plug wire, and check the blade stops when you release the bar.

Blades and torque by mower

Open the engine or model page for the full parts list.

MowerBladeBolt torque
Toro Recycler 22 in. (21442)59534P60 ft-lb (82 N·m)
Honda HRN216Lower 72511-VR8-M00, upper 72531-VR8-M00See your owner's manual

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