Decompression Valve; Ignition System; Spark Plug Boot - Stihl FS 120 Service Manual

4.8

Decompression Valve

 Remove the shroud - see 4.1.
•
Use standard commercial long-
reach 13 mm socket to unscrew
the decompression valve.
 Install new decompression valve
and tighten down to 14 Nm
(10.3 lbf.ft).
 Fit the shroud.
)6       )5  
5.

IGNITION SYSTEM

Warning! Exercise extreme
caution when carrying out
maintenance and repair work on
the ignition system. The high
voltages which occur can cause
serious or even fatal accidents!
Troubleshooting on the ignition
system should always begin at the
spark plug. See "Standard Re-
pairs, Troubleshooting" handbook.
2
Note: The electronic (breakerless)
ignition system basically consists
of an ignition module (1) and
flywheel (2).
The illustration shows the FS 200.
5.1

Spark Plug Boot

 Remove the shroud - see 4.1.
 Pull off the spark plug boot.
 On FS 400/450, FR 450, take
cable holder off the cylinder.
1
•
Use pliers to grip the leg spring
and pull it out of the spark plug
boot.
 Unhook the leg spring from the
ignition lead.
 Pull spark plug boot off the
ignition lead.
 Coat end of the ignition lead
(about 20 mm/3/4") with oil.
 Fit spark plug boot over the
ignition lead.
 Use pliers to grip the end of the
ignition lead inside the spark
plug boot and pull it out.