Stihl RZ 142 Instruction Manual - Page 29

Removing the Mower Blades CAUTION Laceration hazard Mower blades are sharp. Always wear gloves when handling, or working near, mower blades. 1. Use a block of wood to prevent the mower blade from turning as shown in Figure 28. 28 DANGER Thrown objects hazard Avoid injury: a worn or damaged mower blade can break and a piece of the blade could be thrown into the operator's area or bystander's area resulting in serious personal injury or death. • Inspect the mower blade every 25 hours or at least once per year. • If the mower blade hits a solid object, stop the engine immediately and inspect the mower blades. • Never weld or straighten bent mower blades. 3. Inspect the mower blade (Figure 29). Discard the mower blade if it has any of the following conditions: • More than .5" (12,7 mm) of the mower blade metal has been removed from previous sharpening or wear (A). • The air lifts are excessively eroded (B) and the notch (C) is .25" (6,35 mm) deep or greater. • The mower blade is broken or bent. 29 2. Using a wrench, remove the bolt securing the blade to the spindle. Inspecting, Sharpening, and Balancing the Mower Blades CAUTION Laceration hazard. Mower blades are sharp. Always wear gloves when handling, or working near, mower blades. 1. Remove the mower blade from the unit. See Removing the Mower Blades. 2. Clean the blade to remove any dried grass or other debris. 4. If the cutting edges are not sharp or have nicks, sharpen the blades. WARNING Thrown objects and fire hazard Grinding mower blades throws sparks and fine metal particles that are capable of igniting gasoline and gasoline vapors, and that can injure unprotected eyes. Be sure all flammable materials are cleared from the area where grinding will occur. Always wear safety glasses or goggles when grinding mower blades. 29