Husqvarna 55B21HV Owner's Manual page 13

LAWN MOWER
Always observe safety rules when performing any main-
te nance.
TIRES
• Keep tires free of gasoline, oil, or insect control chem-
i cals which can harm rubber.
• Avoid stumps, stones, deep ruts, sharp objects and
other hazards that may cause tire damage.
DRIVE WHEELS
Check rear drive wheels each time be fore you mow to be
sure they move freely.
The wheels not turning freely means trash, grass cuttings,
etc. are in the drive wheel area and must be cleaned to
free drive wheels.
If necessary to clean the drive wheels, be sure to clean
both rear wheels.
BLADE CARE
For best results, mower blade must be kept sharp. Re place
bent or dam aged blades.
TO REMOVE BLADE (See Fig. 18)
1. Disconnect spark plug wire from spark plug and place
wire where it cannot come in contact with spark plug.
2. Turn lawn mower on its side. Make sure air fi lter and
carburetor are up.
3. Use a wood block between blade and mower hous ing
to prevent blade from turning when re mov ing blade
bolts.
NOTE: Protect your hands with gloves and/or wrap blade
with heavy cloth.
4. Remove blade bolts by turning counter-clockwise.
TO REPLACE BLADE (See Fig. 18)
1. Position the blade and spacer. Be sure the trailing
edge of blade (opposite sharp edge) is up toward the
engine and install the blade bolts.
2. Use block of wood between blade and lawn mower hous-
ing and tighten the blade bolts, turning clockwise.
• The recommended tightening torque is 36-44 ft. lbs.
IMPORTANT: BLADE BOLTS ARE HEAT TREATED. IF BOLTS
NEED REPLACING, REPLACE ONLY WITH APPROVED BOLTS
SHOWN IN REPAIR PARTS SECTION OF THIS MANUAL.
TRAILING EDGE
MAINTENANCE
SPACER
BLADE
BLADE
BOLTS
FIG. 18
TO SHARPEN BLADE
NOTE: We do not recommend sharp en ing blade - but if
you do, be sure the blade is balanced.
Care should be taken to keep the blade balanced. An
un bal anced blade will cause eventual damage to lawn
mower or engine.
• The blade can be sharp ened with a fi le or on a grind-
ing wheel. Do not attempt to sharpen while on the
mower.
• To check blade balance, drive a nail into a beam or
wall. Leave about one inch of the straight nail ex posed.
Place center hole of blade over the head of the nail.
If blade is balanced, it should remain in a horizontal
position. If either end of the blade moves downward,
sharpen the heavy end until the blade is balanced.
GRASS CATCHER
• The grass catcher may be hosed with water, but must
be dry when used.
• Check your grass catcher often for damage or de te -
ri o ra tion. Through normal use it will wear. If catcher
needs replacing, replace only with ap proved replace-
ment catcher shown in the Repair Parts section of this
manual. Give the lawn mower model number when
ordering.
ENGINE
LUBRICATION
Use only high quality detergent oil rated with API service
classifi cation SF-SJ. Select the oil's SAE viscosity grade
according to your expected operating temperature.
NOTE: Multi-viscosity oils (5W30, 10W30 etc.) improve
starting in cold weather, and you should check your engine
oil level frequently to avoid possible engine damage from
running low on oil.
Change the oil after every 25 hours of operation or at least
once a year if the lawn mower is not used for 25 hours in
one year.
Check the crankcase oil level before starting the engine
and after each fi ve (5) hours of continuous use. Tighten oil
plug securely each time you check the oil level.
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