MAINTENANCE
16 – English
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. 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.
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 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 carburettor 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 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 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.
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.
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,
clean it and check that the electrode gap is 0,5 mm. The
!
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.
!
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!
H1153993-26,122HD45,60#4ACBF.fm Page 16 Tuesday, January 4, 2011 8:31 AM