Spark Arresting Screen In Muffler; Spark Plug - Stihl MS 291 C-Q Manual De Instrucciones

English
Fine tuning for operation at high
altitude
A slight correction of the setting may be
necessary if engine does not run
satisfactorily:
N
Turn high speed screw (H)
clockwise (leaner) – no further than
stop.
If the setting is too lean there is a
risk of engine damage due to
insufficient lubrication and
overheating.
42
Spark Arresting Screen in
Muffler
In some countries the muffler is
equipped with a spark arresting screen.
N If the engine is down on power,
check the spark arresting screen in
the muffler.
N Wait for the muffler to cool down.
1
2
N Take out the screw (1).
N
Pull out the spark arresting
screen (2).
N Clean the spark arresting screen. If
the screen is damaged or heavily
carbonized, fit a new one.
N Refit the spark arresting screen.
N Insert the screw and tighten it down.

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
N
Remove the shroud – see "Shroud".
N Move the Master Control lever to the
stop position (0).
N Pull off the spark plug boot.
N Clean away loose dirt from around
the spark plug.
MS 291 C-Q