TOP Perfomance PIAGGIO 50 4T Manual Del Usuario página 13

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Piston rings assembly
– Carefully clean the new piston, the piston rings and the
gudgeon pin circlips.
– Assemble one of the two gudgeon pin circlips on the piston,
pay attention not to stretch it, and check that it is placed
correctly in its seat.
– Fit the scraper ring expander in the special piston groove, then
complete the scraper ring assembly by fi tting fi rst the lower and
then the upper scraper
ring (Fig. 3 - Part 1).
– Fit the second piston
ring with the printing
turned towards the pis-
ton crown as indicated
in Fig. 3 - Part. 2.
– Insert the fi rst chromed
compression
ring with the printing
turned towards the pis-
ton upper part as indi-
cated in Fig. 3 - Part. 3.
– Position
rings openings
shown in Fig. 3.
– Note: The letter/sym-
bol printed on the pis-
ton rings may vary.
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Piston-cylinder assy assembly
Warning: cover the casing opening with a clean rag to prevent
the circlip from accidentally falling into it.
– Lubricate the piston gudgeon pin and the con-rod small end
with engine oil.
– Fit the new base gasket and the two dowels.
– Position the piston on the con-rod and insert the new gudgeon
pin. Make sure that the arrow punched on the piston crown is
turned towards the exhaust side.
– Fit the second gudgeon pin circlip and check for it being
correctly positioned in its seat.
– Recheck that the piston rings openings are positioned as
shown in Fig. 3.
– Lubricate piston, piston rings and cylinder.
– Insert the new TOP cylinder by pressing the piston rings (with
piston
the piston
as
13
Fig. 3