Briggs & Stratton MB (18 HP) - Manual (Page 47)

45
Maintenance Instructions
CHECKING/SERVICING
4. If the blade cutting edge is dull or nicked, it
should be sharpened. Remove blades for
sharpening by grasping the end of the blade
using a rag or a thick, padded glove, while loos-
ening and removing the nut, lock washer, and
flat washer that mounts the blade.
5. Grind cutting edge at the same bevel as the
original. Sharpen only the top of the cutting
edge to maintain sharpness.
NOTE: Blades can be sharpened with an elec-
tric blade sharpener, conventional electric
grinder, or a hand file.
6. Check blade balance by positioning the blade
horizontally on a blade balancer or use a nail or
shaft through the center hole. If either end of the
blade rotates downward, grind (remove) metal
on that end until the blade will balance. The
blade is properly balanced when neither end
drops. Balance of a blade is generally main-
tained by removing an equal amount of material
from each end of the blade when sharpening.
Mower Blade Profile For Sharpening
Blade Balanced on Magnetic
Wall-Mounted Balancer
7. Mount the blade with wing tips pointing up into
the housing. Reinstall the blade, washer, lock
washer, and nut. Tighten the nut to 60 ft-lb
(81.3 N
· m).
Drive Belts
Raise the body and inspect the condition of the two
(2) drive belts after every 25 hours of operation --
engine/PTO drive and ground drive. If the belts show
signs of cracking or deteriorating, the belts
should be replaced. Refer to REPLACING/REPAIR-
ING the Drive Belts in this section.
Mower Deck Gearbox Oil Seals
The mower deck gearbox seals should be inspected
every 25 hours for evidence of oil leaking; particu-
larly the lower oil seal on the blade drive gear-
box. This seal is protected by the trash guard on the
blade hub and seal protector plate on the housing,
but is still vulnerable to seal damage due to operating
in an adverse environment. The mower blade must
be removed for inspection of the seal, so it is recom-
mended to inspect the gearbox seals when
blades are removed for sharpening. If an oil leak
is noted, the seal should be replaced and the gear-
box assembly relubricated. Refer to Mower Deck
Gearbox Lubrication in this section.
WARNING
DO NOT try to straighten a blade that is
bent. NEVER weld a broken or cracked
blade. ALWAYS replace with a new blade
to assure safety.
CAUTION
ALWAYS wear eye protection and gloves
when sharpening a blade.
Wing Tip
Do Not Grind or
Sharpen on Underside
30°
Sharpen at Original
30° Angle
Intersection
Wear Area
Blade Balancer