PIAGGIO 500 cc, Service Manual

Page: 76 / 239

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Compression rings assembly
- Put the scraper ring spring on the piston.
- Assemble the scraper ring by keeping the opening
opposite to the spring joint and with the top writing
facing the piston crown. The chamfer must always be
positioned towards the piston crown.
- Assemble the second ring with the identification letter
or the top writing facing the piston crown. The step
must always face the opposite side of the piston
crown.
- Assemble the first compression ring respecting the
direction of its housing.
- We suggest a suitable tool be used to fit the rings.
N.B.: The point of contact of the 2 sealing rings with the
cylinder has a conical shape allowing for a better
bedding.
- Offset the ring openings by 120° as shown in the
figure.
- Lubricate the parts with engine oil.
- The engine requires the 1st compression ring with L
section.
05_195
Cylinder assembly
- Fit the cylinder gasket having the selected thickness.
- Assemble the cylinder by means of the fork and the
ring clamp, as shown in the figure.
Specific tool:
Piston assembly ring
020468Y
Fork 020512Y
N.B. : Before assembling the cylinder, carefully clean
the lubrication duct by blowing in air, and oil the cylinder
liner. Make sure that the two dowels are there.
05_196
Thermal unit and timing system