Piston - Stihl 029, 039 Service Manual

STIHL 029, 039
4.6

Piston

Top:
Removing snap ring
Bottom:
Assembly drift 1110 893 4700
- Pull the piston out of the cylinder -
see 4.5.
- Use a scriber or similar tool to
ease the hookless snap rings
out of the grooves in the piston
bosses.
- Use the assembly drift to push
the piston pin out of the piston. If
the piston pin is stuck, tap the
end of the drift lightly with a
hammer if necessary.
Top:
Pushing out piston pin
Bottom:
Piston rings
1 = "N" marking on piston
head
Important: Hold the piston steady
during this process to ensure that no
jolts are transmitted to the con-
necting rod. Remove the piston and
take the needle cage out of the
connecting rod.
- Inspect piston rings and replace if
necessary - see 4.7.
Note: Only special pistons may be
installed in low compressions saws
(i.e. "N"). The machine numbers of
low compression saws have the suffix
"N". In addition, the piston
Top:
Needle cage in small end
Bottom:
1 = Installing tool 5910 890 2210
2 = Sleeve
head is marked with the letter "N", as
in the inside of the piston.
- Lubricate the needle cage with oil
and fit it in the small end.
- Fit a snap ring in one piston boss.
Note: Use special installing tool
5910 890 2210 to fit the snap ring.
33