Sharpen Lawn Mower Blade

A dull blade tears grass instead of cutting it, leaving ragged brown tips and making the lawn more vulnerable to disease. Disconnect the spark plug before working under the deck. Tilt the mower on its side (carburetor up to prevent oil leaks). Use a blade removal tool or breaker bar to remove the blade bolt. Inspect the blade for nicks, cracks, or a bent edge — replace if bent or heavily nicked. Sharpen with a metal file or angle grinder at the original 30–45° bevel angle. After sharpening, balance the blade on a nail or blade balancer — a heavy side will vibrate and damage the crankshaft over time. Reinstall and torque the bolt to manufacturer spec.