Husqvarna 420 EL Operator's Manual page 95

3. Make sure that the power trigger is locked at the idle
position when the power trigger lockout is released.
(Fig. 88)
4. Start the product and apply full power.
5. Release the power trigger and make sure that the
saw chain stops and stays stationary. If the saw
chain rotates when the power trigger is in the idle
position, turn to your servicing dealer.
To do a check of the chain catcher
1. Make sure that there is no damage on the chain
catcher.
2. Make sure that the chain catcher is stable and
attached to the body of the product. (Fig. 89)
To clean the cooling system
The product has a cooling system that keeps the
temperature of the product as low as possible.
The cooling system includes an air intake on the left side
of the product and a fan on the motor.
1. Clean the cooling system with a brush weekly or
more frequently if necessary.
2. Make sure that the cooling system is not dirty or
blocked.
CAUTION:
cooling system can cause the product to
become too hot. This causes damage to
the piston and cylinder.
To sharpen the saw chain
Information about the guide bar and saw chain
WARNING:
when you use or do maintenance on the
saw chain. A saw chain that does not move
can also cause injuries.
Replace a worn or damaged guide bar or saw chain with
the guide bar and saw chain combination recommended
by Husqvarna. This is necessary to keep the safety
functions of the product. Refer to
page 98 , for a list of replacement bar and chain
combinations that we recommend.
• Guide bar length, in/cm. Information about the guide
bar length can usually be found on the rear end of
the guide bar.
(Fig. 90)
• Number of teeth on bar tip sprocket (T).
(Fig. 91)
• Chain pitch, in. The distance between the drive links
of the saw chain must align with the distance of the
teeth on the bar tip sprocket and drive sprocket.
(Fig. 92)
1782 - 003 - 04.04.2022
A dirty or blocked
Use protective gloves
Accessories on
• Number of drive links. The number of drive links is
decided by the type of guide bar.
(Fig. 93)
• Bar groove width, in/mm. The groove width in guide
bar must be the same as the chain drive links width.
(Fig. 94)
• Chain oil hole and hole for chain tensioner. The
guide bar must align with product.
(Fig. 95)
• Drive link width, mm/in.
(Fig. 96)
General information about how to sharpen the
cutters
Do not use a blunt saw chain. If the saw chain is blunt,
you must apply more pressure to push the guide bar
through the wood. If the saw chain is very blunt, there
will be no wood chips but sawdust.
A sharp saw chain eats through the wood and the wood
chips becomes long and thick.
The cutting tooth (A) and the depth gauge (B) together
makes the cutting part of the saw chain, the cutter. The
difference in height between the two gives the cutting
depth (depth gauge setting).
(Fig. 97)
When you sharpen the cutter, think about the following:
• Filing angle.
(Fig. 98)
• Cutting angle.
(Fig. 99)
• File position.
(Fig. 100)
• Round file diameter.
(Fig. 101)
It is not easy to sharpen a saw chain correctly without
the correct equipment. Use Husqvarna file gauge. This
will help you to keep maximum cutting performance and
the kickback risk at a minimum.
WARNING:
increases a lot if you do not follow the
sharpening instructions.
Note:
To sharpen the cutters on page 95 for
Refer to
information about sharpening of the saw chain.
To sharpen the cutters
1. Use a round file and a file gauge to sharpen the
cutting teeth. (Fig. 102)
The force of the kickback
95