Stihl KM 91 R Notice D'emploi page 17

Spark Arresting Screen in
Muffler
If the engine is down on power,
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check the spark arresting screen in
the muffler.
Wait for the muffler to cool down.
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4
5
Take out the screw (4).
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Lift the spark arresting screen (5)
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and pull it out.
Clean the spark arresting
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screen (5). If the screen is damaged
or heavily carbonized, install a new
one.
Refit the spark arresting screen (5).
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Insert the screw (4) and tighten it
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down firmly.
KM 91 R
Spark Plug
If the engine is down on power,
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difficult to start or runs poorly at idle
speed, first check the spark plug.
Fit a new spark plug after about 100
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operating hours – or sooner if the
electrodes are badly eroded. Install
only suppressed spark plugs of the
type approved by STIHL – see
"Specifications".
Removing the Spark Plug
1
2
3
Remove the cover (1).
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Pull off the spark plug boot (2).
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Unscrew the spark plug (3).
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Checking the Spark Plug
Clean dirty spark plug.
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Check electrode gap (A) and
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readjust if necessary – see
"Specifications".
Rectify the problems which have
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caused fouling of the spark plug.
Possible causes are:
Too much oil in fuel mix.
–
Dirty air filter.
–
Unfavorable running conditions.
–
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 injuries or
damage to property.
English
A
1
15