Instruction Manual

FS 240, FS 240 R
English
39
N Lift the front of the cap (2) and push
it to the rear to disengage.
N Leave the cap to one side.
N Pull off the spark plug boot (3).
N Unscrew the spark plug.
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.
If engine is down on power, difficult to
start or runs poorly at idling speed, first
check the spark plug.
N Remove spark plug – see "Starting /
Stopping the Engine".
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:
N Too much oil in fuel mix.
N Dirty air filter.
N Unfavorable running conditions,
e.g. operating at part load.
Fit a new spark plug after approx. 100
operating hours or earlier if the
electrodes are badly eroded.
WARNING
To reduce the risk of fire and burn injury,
use only spark plugs authorized by
STIHL. Always press spark plug boot (2)
snugly onto spark plug terminal (1) 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
connector in the boot may create arcing
that could ignite combustible fumes and
cause a fire.
Installing the Spark Plug
N Screw the spark plug into the
cylinder.
N Press the spark plug boot firmly
onto the spark plug.
N Fit the cap (1) on the shroud from
the rear and push the lug (2) into the
opening (3) in the shroud at the
same time.
N Swing the cap forwards onto the
shroud, insert and tighten down the
screw (4) firmly.
3
9926BA021 KN
000BA039 KN
A
000BA036 TR
1
4
3
2
9926BA022 KN