Piston Rings - Stihl 064 Service Manual

STIHL 064, 066
Top:
Pressing the manifold downward
Bottom:
Pulling manifold through intake opening
in tank housing
- Fit the manifold in the tank hous-
ing intake opening as follows:
Wind a piece of string (about
15 cm / 6" long) around the back
of the manifold flange, then press
the manifold downward and pass
the ends of the string through the
intake opening.
- Pull the ends of the string out-
ward. The manifold flange is thus
pulled through the tank housing
intake opening without damaging
the manifold.
Tightening the cylinder base screws
with torque wrench 5910 890 0310
- Carefully line up the cylinder and gasket.
- Fit new cylinder base screws of property
class 12.9 and tighten them down
alternately in a diagonal pattern.
Note: Tighten M5 x 20 screws to 12 Nm
(8.8 Ibf.ft) and M6 x 20 screws to 15 Nm
(11.0 Ibf.ft)
Important: It is essential to observe the
above tightening torques as the screws
might otherwise work loose.
Assembly is now a reversal of the
disassembly sequence. Always fit
new gaskets as a matter of routine.
4.4

Piston Rings

Top:
Piston ring grooves
Bottom:
Fitting piston ring
- Remove the piston - see 4.3.1.
- Remove rings from piston.
- Use a piece of an old piston ring
to scrape the grooves clean.
- Install the new piston rings in the
grooves so that the radii face up-
ward.
- Install the piston - see 4.3.2.
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