Tronic; Spark Plug - Stihl MS 241 C-M Instruction Manual

25 M-Tronic
25 M-Tronic
25.1 Basic information
M-Tronic regulates the fuel quantity and ignition
timing for all operating states electronically.
M‑Tronic stands for easy, fast starting, constant
optimum engine performance, outstanding accel‐
eration and automatic adaptation to changes in
operating conditions.
Manual carburetor adjustments are no longer
required – the carburetor does not have any
adjusting screws.
25.2 Automatic adjustment
Under extremely changed operating conditions,
attainment of the optimal setting can be acceler‐
ated as follows:
► Carry out five uniform cuts to length under full
load

26 Spark Plug

► If the engine is down on power, difficult to start
or runs poorly at idle speed, first check the
spark plug.
► Fit a new spark plug after about 100 operating
hours – or sooner if the electrodes are badly
eroded. Install only suppressed spark plugs of
the type approved by STIHL – see "Specifica‐
tions".
26.1 Removing the spark plug
► Remove the shroud – see "Shroud"
► Pull off the spark plug boot
► Unscrew spark plug
0458-738-0121-C
26.2 Checking the Spark Plug
► Clean dirty spark plug.
► Check electrode gap (A) and readjust if neces‐
sary – see "Specifications".
► Rectify the problems which have caused foul‐
ing 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 inju‐
ries or damage to property.
► Use resistor type spark plugs with a properly
tightened adapter nut.
English
A
1
31