Maintenance; Carburettor; Muffler; Cooling System - Husqvarna 525BX Operator's Manual

H1156688-26,525BX,GB.fm Page 39 Wednesday, August 12, 2015 3:33 PM

Carburettor

Adjustment of the idle speed
Before any adjustments are made, make sure that the air
filter is clean and the air filter cover is fitted. Adjust the idle
speed using the idle adjustment screw T, if it is necessary
to readjust.
T
Recommended idle speed: See the Technical data
section.
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
mesh. If your machine has this type of muffler, you should
clean the mesh at least once a week. This is best done
with a wire brush. On mufflers without a catalytic
converter the mesh should be cleaned weekly, or
replaced if necessary. On mufflers fitted with a catalytic
converter the mesh should be checked, and if necessary
cleaned, monthly. If the mesh is damaged it should be
replaced. If the mesh 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

MAINTENANCE

blocked mesh 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.
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.

Spark plug

The spark plug condition is influenced by:
• Incorrect carburettor adjustment.
• An incorrect fuel mixture (too much or incorrect type
of oil).
• A dirty air filter.
These factors cause deposits on the spark plug
electrodes, which may result in operating problems and
starting difficulties.
If the machine is low on power, difficult to start or runs
poorly at idle speed: always check the spark plug first
before taking any further action. If the spark plug is dirty,
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