Spark Arresting Screen In Muffler; Spark Plug - Stihl MS 171 Instruction Manual

Spark Arresting Screen in
Muffler

Spark arresting screen in muffler

If the engine is down on power,
N
check the spark arresting screen in
the muffler.
STIHL recommends that you have
servicing and repair work carried out
exclusively by an authorized STIHL
servicing dealer.
MS 171, MS 181, MS 181 C, MS 211, MS 211 C

Spark Plug

If engine is down on power, difficult to
start or runs poorly at idling speed, first
check the spark plug.
Fit a new spark plug after approx. 100
operating hours or earlier if the
electrodes are badly eroded.
Wrong fuel mix (too much engine oil in
the gasoline), a dirty air filter and
unfavorable running conditions (mostly
at part throttle etc.) affect the condition
of the spark plug. These factors cause
deposits to form on the insulator nose
which may result in trouble in operation.
Removing the spark plug
Remove the shroud – see "Shroud".
N
Pull off the spark plug boot.
N
Unscrew the spark plug.
N
Checking the Spark Plug
Clean dirty spark plug.
N
Check electrode gap (A) and
N
readjust if necessary – see
"Specifications."
Use only resistor type spark plugs of
N
the approved range.
Rectify problems that have caused
fouling of spark plug:
too much oil in fuel mix,
–
dirty air filter,
–
unfavorable running conditions, e.g.
–
operating at part load.
English
A
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