Spark Plug - Stihl MS 311 Instruction Manual

Spark Plug

If the engine is down on power,
N
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".
Remove the spark plug
Move the Master Control lever to the
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stop position 0
Push the hand guard forwards – the
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saw chain is blocked
2
1
Loosen screws (1)
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Remove the shroud (2)
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MS 311, MS 391
Pull off the spark plug boot
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Unscrew spark plug
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Checking the Spark Plug
1
Clean dirty spark plug.
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Check electrode gap (A) and
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readjust if necessary – see
"Specifications".
1
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.
Use resistor type spark plugs with a
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properly tightened adapter nut.
Install spark plug
A
Screw in the spark plug and press
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on the spark plug boot
Refit the shroud and tighten the
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screws
English
1
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