Stihl MS 390 User Manual

33MS 290, MS 310, MS 390
– Pull the piston out of the cylinder,
b 6.5.1
: Ease the hookless snap rings out
of the grooves.
VA
135RA085
: Use the assembly drift (2)
1110 893 4700 to push the piston
pin (1) out of the piston.
If the piston pin is stuck, release it
by tapping the end of the drift lightly
with a hammer. Hold the piston
steady during this process to ensure
that no jolts are transmitted to the
connecting rod.
– Remove the piston from the
connecting rod.
– Inspect needle cage and replace
if necessary.
: Inspect piston rings and replace if
necessary, b 6.6
VA
135RA087
: Fit needle cage (arrow) in the
connecting rod.
– Lubricate needle cage with oil.
: Push the piston over the
connecting rod.
Installed position of piston:
1 = Mark (arrow)
2 = Long stub of crankshaft
: Push the assembly drift, small
diameter first, through the piston
and small end (needle cage) and
line up the piston.
: Fit the piston pin (1) on the
assembly drift (2) and slide it into
the piston (the pin slides home
easily if the piston is warm).
: If necessary, modify the sleeve of
the installing tool 5910 890 2210
as shown:
a = 16 mm
b = 8 mm
VA
135RA093
a
b
6.5.2 Piston

Stihl MS 390 Specifications

General

Brand	Stihl
Model	MS 390
Category	Chainsaw
Language	English