Lawn mowers require routine maintenance to perform at their peak. The blades of the mower should be inspected with each mowing to ensure they are sharp and cutting the grass. Dull or damaged blades will tear at the grass, leaving a less-than-desirable lawn appearance. If this occurs, it's time to change the blades.
Remove the sparkplug wire from the sparkplug to prevent the mower from accidentally starting.
Siphon the gas and oil out of the mower, using a different siphon for each liquid. Store in approved containers until ready to reuse. Tilt the mower onto its side, bracing it with a cement block.
Push a wood block through the discharge opening and wedge it against the blade to secure it from moving.
Unscrew the nut in the center of the blade, using a screwdriver and turning clockwise until removed. Slide the blade off the spindle.
Place the new blade on the spindle, curved side facing the mower deck. Replace the nut onto the spindle and hand-tighten. Place the wood block against the blade, through the discharge to prevent it from turning. Tighten the nut with the wrench to secure the blade.
Remove the wooden block and turn the blade by hand. Inspect the blade to ensure it is tightly secured to the spindle and does not wobble.
Turn the mower right-side up. Fill the gas and oil reservoirs with the correct fluid and replace the sparkplug wire.