Spark Plug - Stihl FS 40 Manual De Instrucciones

English
Cutting attachment rotates when engine
is idling
Turn the idle speed screw (LA)
N
counterclockwise until the tool stops
moving and then turn the screw
another full turn in the same
direction.
If the cutting tool continues to rotate
when the engine is idling, have your
machine checked and repaired by your
servicing dealer.
Erratic idling behavior, engine stops
even though setting of LA-screw has
been corrected, poor acceleration
Idle setting is too lean
Turn the low speed screw (L)
N
counterclockwise, no further than
stop, until the engine runs and
accelerates smoothly.
Erratic idling behavior, engine speed
drops when swinging the machine
Idle setting is too rich
Turn the low speed screw (L)
N
clockwise (1/8 of a turn or 45° at a
time) until the engine runs smoothly
and accelerates well.
It is usually necessary to change the
setting of the idle speed screw (LA) after
corrections to the low speed screw (L).
28

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
Shut off the engine
N
The spark plug boot (2) sits inside the
cap (1).
The cap (1) protects the spark plug boot
from damage. Do not operate the
machine without a cap – replace a
damaged cap.
Pull off the spark plug boot (2)
N
together with the cap (1).
Unscrew the spark plug (3).
N
If the cap becomes detached while
pulling off the spark plug boot, see
"Installing the Spark Plug".
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 which have caused
1
fouling of spark plug:
Too much oil in fuel mix.
–
Dirty air filter.
–
Unfavorable running conditions,
–
e.g. operating at part load.
FS 40, FS 40 C, FS 50, FS 50 C
A