CHT220/CHT220L
9. Maintenance
■ CARBURETOR
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. Make sure the
start throttle position is disengaged.
Adjust the idle speed using the idle adjustment screw T, if it
is necessary to readjust. First turn the T screw clockwise
until the cutting attachment starts to move. Then turn the
screw anticlockwise until the cutting attachment stops.
The idle speed is correctly adjusted when the engine runs
smoothly in every position. The idle speed should also be
well below the speed at which the cutting attachment starts
to move.
Rec. idle speed: See the Technical data section.
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
mesh. If your machine has this type of muffler, the mesh
must be cleaned. This is best done with a wire brush.
On mufflers without a catalytic converter, the mesh should
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be cleaned or replaced if necessary once a week. If the
mesh is damaged it must be replaced. If the mesh is
frequently blocked, this can be a sign that the carburetor is
incorrectly adjusted or that too much oil has been mixed
with the petrol.
On mufflers fitted with a catalytic converter, the mesh must
be checked, and if necessary cleaned, monthly. If the mesh
is damaged it must 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.
The cooling system consists of:
1 Cooling fins on the cylinder.
2 Cylinder cover (directs cold air over the cylinder).
3 Air intake through the crankcase (inside the tank).
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.