Ignition System - Stihl MS 201 Manual

3.5

Ignition System

Condition
Engine runs roughly, misfires,
temporary loss of power
MS 201, MS 201 C, MS 201 T, MS 201 TC
Cause
Spark plug boot is loose
Spark plug sooted, smeared with oil Clean spark plug, replace if
Fuel/oil mixture
– too much oil
Incorrect air gap between ignition
module and flywheel
Flywheel cracked or
damaged or pole shoes have
turned blue
Ignition timing wrong, flywheel out
of adjustment
– key in flywheel has sheared off
Weak magnetization in flywheel
Irregular spark
Crankcase damaged (cracks)
Remedy
Press boot firmly onto spark plug
and fit new spring if necessary
necessary. If sooting continues,
check air filter
Use correct mixture of fuel and oil
Set air gap correctly
Install new flywheel
Install new flywheel
Install new flywheel
Check operation of switch shaft /
contact spring(s) and ignition
module.
Check ignition lead and short circuit
wire for damaged insulation or
break.
Check ignition lead / module,
replace ignition module if
necessary. Check operation of
spark plug, clean or replace spark
plug if necessary.
Install new crankcase
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