Spark Plug
If the engine is down on power,
N
difficult to start or runs poorly at idle
speed, first check the spark plug.
Fit a new spark plug after about 100
N
operating hours – or sooner if the
electrodes are badly eroded. Install
only suppressed spark plugs of the
type approved by STIHL – see
"Specifications".
Removing the spark plug
1
Pull off the spark plug boot (1).
N
Unscrew the spark plug.
N
BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
Checking the Spark Plug
Clean dirty spark plug.
N
Check electrode gap (A) and
N
readjust if necessary – see
"Specifications".
Rectify the problems which have
N
caused fouling of the spark plug.
Possible causes are:
Too much oil in fuel mix.
–
Dirty air filter.
–
Unfavorable running conditions.
–
WARNING
Arcing may occur if the adapter nut (1) is
loose or missing. Working in an easily
combustible or explosive atmosphere
may cause a fire or an explosion. This
can result result in serious injuries or
damage to property.
Use resistor type spark plugs with a
N
properly tightened adapter nut.
Installing the spark plug
A
Screw the spark plug (3) into the
N
cylinder and fit the boot (2) (press it
down firmly).
1
English
2
3
17