Operation Manual

14 MS 241 C
3.5 Ignition system
Problem Cause Remedy
Engine runs roughly, misfires,
temporary loss of power
Spark plug boot is loose Press boot firmly onto spark plug
and fit new spring if necessary
Spark plug sooted, smeared with oil Clean the spark plug or replace if
necessary
In the event of repeated sooting,
check air filter
Fuel/oil mixture
– contains too much oil
Use a fuel mixture with the correct
mixing ratio
Wrong air gap between control unit
and flywheel
Set the correct air gap
Flywheel is cracked
or has other damage or pole shoes
have turned blue
Install new flywheel
Incorrect ignition timing, flywheel
out of adjustment
– Key in flywheel has sheared off
Install new flywheel
Weak magnetization in flywheel Install new flywheel
Irregular spark Check operation of switch shaft/
contact spring and control unit
Damaged insulation or interruption
in ignition lead or short circuit wire.
Check ignition lead/control unit,
replace control unit if necessary.
Check operation of spark plug,
clean spark plug and replace if
necessary. Check M-Tronic