Honda HRC216PDA Owner's Manual page 23

Obstacles
Use the side of the mower to cut close to large obstacles, such as
fences or walls.
Be careful when mowing over obstacles embedded in the lawn, such
as sprinkler heads, paving, edging, raised tree roots, etc. Avoid
anything that sticks up above the surface of the lawn.
If the blade hits something, or if the mower starts to vibrate, stop the
engine immediately, disconnect the spark plug cap, and check for
damage (page 28). Striking objects may damage the blades, bend the
crankshaft, and/or break the mower deck or other components.
Vibration usually indicates serious trouble.
A worn, cracked, or damaged blade can
break, and pieces of the damaged blade
can become dangerous projectiles.
Thrown objects can cause serious injury.
Inspect the blades regularly, and do not
operate the mower with a worn or damaged
blade.
The Distributor's Limited Warranty does not cover parts damaged by
accident or collision.
Gravel and Loose Objects
Gravel, loose stones, and landscaping material can be picked up by
the mower and thrown great distances with enough force to cause
serious personal injury and/or property damage. To prevent potential
injury from thrown objects, release the blade control lever to stop the
engine before reaching areas with gravel, loose stones, or landscaping
material.
 WARNING
OPERATION
21