The catayltic converter integrated in the muffler
reduces the harmful emissions in the exhaust
gas.
The correct carburetor setting (if adjustable) and
strict observance of the prescribed mix ratio of
gasoline and two-stroke engine oil are essential
to minimize harmful emissions and ensure a long
catalytic converter service life.
14 Spark Plug
► If the engine is down on power, difficult to start
or runs poorly at idle speed, first check the
spark plug.
► Fit a new spark plug after about 100 operating
hours – or sooner if the electrodes are badly
eroded. Install only suppressed spark plugs of
the type approved by STIHL – see "Specifica‐
tions".
14.1
Removing the Spark Plug
1
9928BA014 AM
► Pull off the spark plug boot (1).
► Unscrew the spark plug.
14.2
Checking the Spark Plug
000BA039 KN
A
► Clean dirty spark plug.
► Check electrode gap (A) and readjust if neces‐
sary – see "Specifications".
► Rectify the problems which have caused foul‐
ing of the spark plug.
Possible causes are:
–
Too much oil in fuel mix.
–
Dirty air filter.
–
Unfavorable running conditions.
1
000BA045 KN
WARNING
Arcing may occur if the adapter nut (1) is loose
or missing. Working in an easily combustible or
explosive atmosphere may cause a fire or an
explosion. This can result result in serious inju‐
ries or damage to property.
► Use resistor type spark plugs with a properly
tightened adapter nut.
14.3
Installing the spark plug
► Screw home the spark plug, fit the boot and
press it down firmly.
15 Engine Running Behavior
If engine running behavior is unsatisfactory even
though the air filter is clean and the carburetor is
properly adjusted, the cause may be the muffler.
Have the muffler checked for contamination (car‐
bonization) by your servicing dealer.
STIHL recommends that you have servicing and
repair work carried out exclusively by an author‐
ized STIHL servicing dealer.
16 Storing the Machine
For periods of 3 months or longer
► Drain and clean the fuel tank in a well ventila‐
ted area.
► Dispose of fuel properly in accordance with
local environmental requirements.
► Run the engine until the carburetor is dry – this
helps prevent the carburetor diaphragms stick‐
ing together.
► Thoroughly clean the machine – pay special
attention to the cylinder fins and air filter.
► Store the machine in a dry, high or locked
location, – out of the reach of children and
other unauthorized persons.
14 Spark Plug
English
0458-455-0121-D
13
