Owner's Manual

MS 291 C-Q
English
43
N Insert the combination wrench
through the grommet (1) and turn it
as necessary to engage the spark
plug's hexagon.
N Push the combination fully home
against the cylinder.
N Unscrew the spark plug.
Checking the Spark Plug
N Clean dirty spark plug.
N Check electrode gap (A) and
readjust if necessary – see
"Specifications".
N Use only resistor type spark plugs of
the approved range.
Rectify problems which have caused
fouling of spark plug:
– Too much oil in fuel mix.
– Dirty air filter.
– Unfavorable running conditions,
e.g. operating at part load.
Installing the spark plug
N Insert the spark plug through the
grommet and screw it in by hand.
N Tighten down the spark plug, fit the
boot and press it down firmly.
N Install the shroud – see "Shroud".
5902BA014 KN
1
000BA039 KN
A
Warning!
To reduce the risk of fire and burn injury,
use only spark plugs authorized by
STIHL. Always press spark plug boot (1)
snugly onto spark plug terminal (2) of
the proper size. (Note: If terminal has
detachable SAE adapter nut, it must be
attached.) A loose connection between
spark plug boot and ignition wire con-
nector in the boot may create arcing that
could ignite combustible fumes and
cause a fire.
1
2
000BA071 KN
5902BA016 KN