Honda HRM4000EC Owner's Manual page 102

Checking the blades and blade disc
Check the condition of the blades and blade disc as follows.
Lifetime of the blades
In order to have good cutting performance, maintain the sharp cutting edge on the blades. Typically, the
lifetime of the blades is 160 hours. (2 weeks to 2 months) Because the lifetime depends on grass condition,
it may be necessary to exchange earlier than usual, especially in the spring season.
If your lawn will become the condition of white fiber it is a sign to change blades.
Example: if the lawnmower works for 11.4 hours per day every day, the lifetime of the blades is 2 weeks.
If the lawnmower works for 2.6 hours per day every day, the lifetime of the blades is 2 months.
N WARNING
- Do not touch the blades with your bare hands. Put on a pair of work gloves.
- Make sure to press the manual STOP button and press the B (Off) button to turn the power off
before performing the following procedures.
NOTE:
- Hold the lawnmower against a wall for support.
- Do not lift the lawnmower off of the ground while checking it.
Check the blades, nuts and blade disc for problems.
Check item(s)
Damage to the blades
Loosened bases of the
blades
Blades and nuts
Abrasions of the holes of
blades and abrasions of the
shoulders of nuts
Blade disc Warping of the blade disc
Blade disc
Base of the
blade
Normal
Visually inspect the blades.
If they are damaged, replace the blades. See
"Replacing the blades" (M page 100).
Rotate the nuts with your finger to check that they are
not loose.
If the nuts are loose, tighten them to the specified
torque value. See "Replacing the blades" (M page 100).
Visually inspect the abrasions of the hole of blades
and the abrasions of the shoulder of nuts.
While mowing, the hole of the blades will widen and
the shoulder of the nuts will decrease in size because
of abrasions, and there is a danger that the blades will
be detached from the blade disc.
If they are worn, replace the blades and nuts. See
"Replacing the blades" (M page 100).
Rotate the blade disc and visually check it.
If it is warped, consult your dealer.
Checking the abrasions of
blades and nuts
21.7mm-24.6mm
Correct
worn Excessively worn
Maintenance procedures
Action
Checking the abrasions of
the shoulders of nuts
24.7mm or more
Incorrect Correct
Damaged blades
Cracked
Incorrect
Bent
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