Lawn Mower, Engine, Tires, Blade Care | Husqvarna 5521CM instruction

MAINTENANCE

LAWN MOWER

Always observe safety rules when performing any main- tenance.

TIRES

•Keep tires free of gasoline, oil, or insect control chem- icals which can harm rubber.

•Avoid stumps, stones, deep ruts, sharp objects and other hazards that may cause tire damage.

BLADE CARE

For best results, mower blade must be kept sharp. Replace bent or damaged blades.

TO REMOVE BLADE (See Fig. 11)

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 housing to prevent blade from turning when removing blade bolt.

NOTE: Protect your hands with gloves and/or wrap blade with heavy cloth.

4.Remove blade bolt by turning counter-clockwise.

5.Remove blade and attaching hardware (bolt, lock washer and hardened washer).

NOTE: Remove the blade adapter and check the key inside hub of blade adapter. The key must be in good condition to work properly. Replace adapter if damaged.

TO REPLACE BLADE (See Fig. 11)

1.Position the blade adapter on the engine crankshaft. Be sure key in adapter and crankshaft keyway are aligned.

2.Position blade on the blade adapter aligning the two

(2)holes in the blade with the raised lugs on the adapter.

3.Be sure the trailing edge of blade (opposite sharp edge) is up toward the engine.

4.Install the blade bolt with the lock washer and hardened washer into blade adapter and crankshaft.

5.Use block of wood between blade and lawn mower housing and tighten the blade bolt, turning clockwise.

•The recommended tightening torque is 35-40 ft. lbs.

IMPORTANT: BLADE BOLT IS GRADE 8 HEATTREATED.

TO SHARPEN BLADE

NOTE: We do not recommend sharpening blade - but if you do, be sure the blade is balanced.

Care should be taken to keep the blade balanced. An unbalanced blade will cause eventual damage to lawn mower or engine.

•The blade can be sharpened with a ﬁ le or on a grinding 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 exposed. 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.

BLADE ADAPTER		CRANKSHAFT
		KEYWAY
KEY
BLADE
LOCK
WASHER
BLADE		CRANK-
BOLT		CRANK-
BOLT		SHAFT
HARDENED		SHAFT
HARDENED	TRAILING EDGE	BLADE ADAPTER
WASHER	TRAILING EDGE	BLADE ADAPTER

FIG. 11

GRASS CATCHER

•The grass catcher may be hosed with water, but must be dry when used.

•Check your grass catcher often for damage or dete- rioration. Through normal use it will wear. If catcher needs replacing, replace only with a manufacturer approved replacement catcher. 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.