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 blocked mesh will cause
the machine to overheat and result in damage to the cylinder
and piston. See also instructions under the heading
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
To keep the working temperature as low as possible the
machine is equipped with a cooling system.
The cooling system consists of:
1 Air intake on the starter.
2 Fins on the ﬂywheel.
3 Cooling ﬁns on the cylinder.
4 Cylinder cover (directs cold air over the cylinder).
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.
The spark plug condition is inﬂuenced by:
Incorrect carburetor adjustment.
An incorrect fuel mixture (too much or incorrect type of
A dirty air ﬁlter.
These factors cause deposits on the spark plug electrodes,
which may result in operating problems and starting
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 (0,020"). The spark plug
should be replaced after about a month in operation or earlier
CAUTION! Always use the recommended spark plug type!
Use of the wrong spark plug can damage the piston/cylinder.
Check that the spark plug is ﬁtted with a suppressor.
The air ﬁlter must be regularly cleaned to remove dust and dirt
in order to avoid:
Loss of engine power
Unnecessary wear to engine parts
Excessive fuel consumption.
Clean the ﬁlter every 25 hours, or more regularly if conditions
are exceptionally dusty.