Husqvarna LB 448S Operator's Manual page 14

WARNING: Use protective gloves when you
do maintenance on the cutting equipment.
The blade is very sharp and cuts can easily
occur.
1. Examine the cutting equipment for damage or
cracks. Always replace a damaged cutting
equipment.
2. Look at the blade to see if it is damaged or blunt.
Note: It is necessary to balance the blade after it is
sharpened. Let a service center sharpen, replace and
balance the blade. If you hit an obstacle that causes the
product to stop, replace the damaged blade. Let the
service center estimate if the blade can be sharpened or
must be replaced.
To replace the blade
1. Lock the blade with a block of wood.(Fig. 33 )
2. Remove the blade bolt, the spring washer and the
blade.(Fig. 34 )
3. Examine the blade support and blade bolt for
damages.
a) If you replace the blade or the blade support,
also replace the blade bolt, the spring washer
and the friction washer.
4. Examine the engine shaft to make sure that it is not
bent.
5. When you attach the new blade, make sure that the
bent ends point in the direction of the cutting cover.
(Fig. 35 )
6. Put the friction washer and the blade against the
blade support.(Fig. 36 )
7. Make sure that the blade aligns with the center of the
engine shaft.(Fig. 37 )
8. Lock the blade with a block of wood.(Fig. 38 )
9. Attach the spring washer and tighten the bolt with a
torque of 80 Nm.(Fig. 39 )
10. Pull the blade around by hand and make sure that it
turns freely.
WARNING: Use protective gloves. The
blade is very sharp and cuts can easily
occur.
11. Start the product to do a test of the blade. If the
blade is not correctly attached, there is vibration in
the product or the cutting result is unsatisfactory.
To do a check of the oil level
CAUTION: A too low oil level can do
damage to the engine. Do a check of the oil
level before you start the product.
1. Put the product on level ground.
14
2. Close the fuel valve.
3. Remove the oil tank cap with the attached dipstick.
4. Clean the oil from the dipstick.
5. Put the dipstick into the oil tank but do not tighten the
oil tank cap.
6. Remove the dipstick.
7. Examine the oil level on the dipstick.
8. If the oil level is low, fill with engine oil and do a
check of the oil level again. The oil level is correct
when it is at the top mark on the dipstick.
To change the engine oil
WARNING: Engine oil is very hot directly
after the engine is stopped. Let the engine
become cool before you drain the engine oil.
If you spill engine oil on your skin, clean with
soap and water.
1. Operate the product until the fuel tank is empty.
2. Remove the ignition cable from the spark plug.
3. Remove the oil tank cap.
4. Put a container below the product to collect the
engine oil in.
5. Tilt the product to drain the engine oil from the oil
tank.
6. Fill with new engine oil of the type recommended in
Technical data on page 15 .
7. Do a check of the oil level. See
oil level on page 14 .
To clean the air filter
CAUTION: Do not operate the engine
without an air filter attached or if the air filter
is dirty.
CAUTION: Replace the air filter if it cannot
be fully cleaned or if it is damaged. A
defective air filter causes damage to the
engine.
1. Push the latch tabs (A), remove the air filter cover
(B) and remove the air filter (C).(Fig. 40 )
2. Hit the air filter against a hard surface or blow
compressed air through the air filter from the clean
side of the air filter.
CAUTION: Do not use a brush to
remove dirt as this pushes the dirt into
the air filter.
3. Clean the air filter holder (D) and the air filter cover
with a moist cloth.
To do a check of the
741 - 002 - 11.10.2018