25Series 4144 Powerhead
: Use the assembly drift (2)
1130 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 (1) from the
connecting rod.
– Inspect the piston and replace it if
necessary
– Inspect the piston ring and
replace if necessary, b 6.7.1
2
1
938RA064 TG
1
938RA065 TG
: Check the needle cage (1) and
clean it if necessary
A new crankshaft must be installed
if the needle cage is damaged,
b 9.
– Lubricate the needle bearing
with oil.
: Line up the piston as shown so
that the arrow (arrow) on the
piston crown faces the crankcase
rib (1) and the short crankshaft
stub (2) is on the right.
: Place the piston on the
connecting rod.
1
938RA066 TG
1
2
938RA067 TG
: Push the assembly drift (1)
1130 893 4700, small diameter
first, through the piston and small
end (needle cage).
: Fit the piston pin (2) on the
assembly drift (1) and slide it into
the piston.
: Remove the sleeve (1)
5910 893 1708 from the installing
tool (2) 5910 890 2208.
1
938RA068 TG
1
2
938RA069 TG
296RA077 TG
12