Piston Rings; Crankcase; Removing Crankshaft - Stihl FS 120 Service Manual

4.6

Piston Rings

 Remove the piston - see 4.5.1.
Note: The piston must be re-
moved to make sure that no
residue can fall into the crankcase
when installing the piston rings
and cleaning their grooves.
Illustrations show piston
in model FS 200.
 Remove rings from piston.
•
Use a piece of old piston to
scrape the grooves clean.
1 1
2
•
Install the new piston rings in the
grooves so that the radii (1) face
the fixing pin (2).
 Install the piston - see 4.5.2.
)6       )5  
4.7

Crankcase

4.7.1

Removing Crankshaft

 Remove the ignition module -
see 5.3.2 and 5.3.3.
 Remove the fuel tank - see 8.5.
 Remove the cylinder - see 4.5.1.
2
All models
•
Take out screw (1).
•
Remove top of cable guide (2).
FS 120...350, FR 350
2
4
•
Take throttle cable (1) out of
base of guide (2).
•
Take short circuit wire (3) out of
base of guide and remove it from
the retainers (4).
FS 400/450, FR 450
•
Remove short circuit wire from
the retainers.
1
•
Ease the grommets out of the
housing and pull out the short
circuit wire.
1
3
All models
•
Pull the base of the guide
off the housing.
 Remove the carrier - see 3.2.