Maintenance; Carburetor; Muffler; Cooling System - Husqvarna 426LST Operator's Manual

Carburetor

Adjustment of the idle speed
Check that the air filter is clean. When the idle speed is
correct, the cutting attachment should not rotate. If
adjustment is required, close (turn clockwise) the idle
adjustment screw T, with the engine running, until the
cutting attachment starts to rotate. Open (turn
anticlockwise) the screw until the cutting attachment
stops. The idle speed is correctly set when the engine
runs smoothly in all positions, and there is a clear margin
to the speed at which the cutting attachment starts to
rotate.
WARNING! If the idle speed cannot be
!
adjusted so that the cutting attachment
stops, contact your dealer/service
workshop. Do not use the machine until
it has been correctly adjusted or
repaired.
Muffler
CAUTION! Some mufflers are fitted with a catalytic
converter. See chapter on Technical data to see whether
your machine is fitted with a catalytic converter.
The muffler is designed to reduce the noise level and to
direct the exhaust gases away from the operator. The
exhaust gases are hot and can contain sparks, which may
cause fire if directed against dry and combustible
material.
Some mufflers are equipped with a special spark arrestor
screen. If your machine has this type of muffler, you
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MAINTENANCE

T
should clean the screen at least once a week. This is best
done with a wire brush.
On mufflers without a catalytic converter the screen
should be cleaned weekly, or replaced if necessary. On
mufflers fitted with a catalytic converter the screen should
be checked, and if necessary cleaned, monthly. If the
screen is damaged it should be replaced. If the screen
is frequently blocked, this can be a sign that the
performance of the catalytic converter is impaired.
Contact your dealer to inspect the muffler. A blocked
screen will cause the machine to overheat and result in
damage to the cylinder and piston.
CAUTION! Never use a machine with a defective muffler.
WARNING! Mufflers fitted with catalytic
!
converters get very hot during use and
remain so for some time after stopping.
This also applies at idle speed. Contact
can result in burns to the skin.
Remember the risk of fire!

Cooling system

To keep the working temperature as low as possible the
machine is equipped with a cooling system.
2
The cooling system consists of:
1 Cooling fins on the cylinder.
2 Cooling air intake
Clean the cooling system with a brush once a week, more
often in demanding conditions. A dirty or blocked cooling
system results in the machine overheating which causes
damage to the piston and cylinder.
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