Lawnmower blades develop wear, curling, and nicks after prolonged use. Simply sharpening them won't restore their sharpness. Continued use will affect cutting performance, damage the lawn, increase machine load, and cause malfunctions. Many beginners believe blade replacement requires professional skills and hesitate to do it themselves, opting instead to hire a professional. However, with the correct steps, even beginners can easily replace blades, saving time and money. Today, we'll explain in detail how to replace lawnmower blades, with clear steps and simple operation that even beginners can master.
Before replacement, prepare for safety. First, turn off the lawnmower power (turn off the engine for fuel-powered models, remove the battery for electric models). Wait for the blades to completely stop rotating. Wear non-slip gloves to prevent cuts from dull blades. Prepare the following tools: a wrench of the appropriate size (for loosening the fixing bolts), new compatible blades (make sure to choose blades that match your lawnmower model to avoid size incompatibility), a brush (for cleaning debris from the blade disc), and if available, a clamp (for securing the blade for easier handling).
Step 1: Remove the old blades. Place the lawnmower on a flat surface, ensuring stability and avoiding tilting. Locate the blade fixing bolts (usually located in the center of the blade disc). Loosen the bolts counter-clockwise with a wrench, noting the bolt installation sequence and direction to avoid later installation errors. After loosening the bolts, gently remove the old blades. If the blades are stuck to the blade disc, use a brush to clean weeds and dirt from the disc surface before gently prying the blades off. Do not use excessive force to avoid damaging the blade disc.
Step 2: Clean the blade disc and check its condition. After removing the old blades, thoroughly clean the inside of the blade disc with a brush to remove weeds, dirt, and metal shavings. Ensure the blade disc is clean and free of debris to prevent it from affecting the installation and operation of the new blades. Also, check the blade disc for deformation, rust, cracks, or other problems. If the blade disc is deformed or damaged, repair or replace it before installing the new blades to avoid affecting cutting performance and machine safety.
Step 3: Install the new blades and secure them firmly. Install the new blade onto the cutter head in the same direction as when it was disassembled, ensuring the blade is properly installed and the blade edge is facing correctly (usually downwards; refer to the lawnmower's instruction manual for details). Pass the fixing bolt through the blade mounting hole and tighten it clockwise. Tighten the bolt with moderate force-enough to ensure the blade is securely fixed and prevent wobbling during operation, but avoid excessive force to prevent stripping the bolt threads or deforming the blade. After installation, manually rotate the blade to check for smooth operation, no jamming, and no wobbling, ensuring correct installation.
After replacement, perform a test run. Start the lawnmower and run it idle for 1-2 minutes, observing whether the blade runs smoothly and without abnormal noise. If it runs normally, perform a small-scale cutting test to check the cutting effect. If abnormal noise, wobbling, or uneven cutting occurs, immediately turn off the power and check whether the blade is securely installed and correctly oriented, adjusting as needed. During daily use, it is recommended to check the blade condition every 100-150 hours of operation, replacing it promptly if severely worn to ensure cutting performance and machine safety.
