DR Whisper Lite CEM1000, Safety & Operating Instructions Manual

Page: 17 / 24

DR
®
WHISPER LITE
®
CORDLESS Electric Mower Safety & Operating Instructions 11
!
WARNING: Be certain to remove the power key and the battery pack before performing any
adjustment or repair.
To Sharpen the Blade
When the blade is dull, cut ends of the grass
will be ragged and usually turn brown soon
after mowing. If the blade is in otherwise good
condition, sharpen it when the cutting edges
become dull.
!
Caution: To avoid cutting yourself on the
blade, wear heavy leather gloves.
For best results, remove the blade (Figure 17)
and sharpen the cutting surfaces at an angle of
25 degrees.
Check the blade after sharpening to make sure
it is still balanced (see "To Balance the Blade"
below). It will cause excessive vibration if
unbalanced.
Before reassembling the blade and the blade
adapter to the unit, brush any built up debris
out of the grooves of the motor base
(Figure
18). Coat the motor crankshaft and the inner
surface of the blade adapter with light oil (or
engine oil).
Install the sharpened or replacement blade with
components in same sequence as removed
. Do
not substitute any components here. Tighten
the blade retaining cap screw.
Important: When replacing the blade, be sure to install it with the stiffening ribs on the blade
facing toward the mower.
To Balance the Blade
Because you are removing metal from each side of the blade, make sure to remove an equal amount
from each side to keep the blade balanced. A badly imbalanced blade will cause your machine to
vibrate excessively. The best way to balance a blade is with a blade balancer (usually about $3.00 at
your local hardware store) or with a large nail or bolt. After sharpening the blade, place it on the
balancer and check the level. If one side of the blade tips lower, you need to sharpen that side more
to balance the blade.
Figure 17
Figure 18
Loosen the blade mounting bolt
with a 1/2" socket wrench
Blade adapter
Clean grooves in the motor base