PIAGGIO NRG 50, User Manual

Page: 131 / 275

Inspecting the cylinder
- Check that the cylinder does not show seizures.
Otherwise, replace it or adjust it respecting the al-
lowable increases
- Measure the internal diameter of the cylinder with
a bore meter, according to the directions given in
the figure
- Check that the fitting surface with the head is not
dented or distorted.
To classify the cylinder-piston fitting, check the ap-
propriate table
Inspecting the piston rings
- Alternatively insert the two sealing rings in the
cylinder
Using the piston, insert the seals perpendicularly
to the cylinder axis.
- Measure the opening of the sealing rings using a
feeler gauge as shown in the photograph
- If the values are higher than the values prescri-
bed in the chart, substitute the rings
Removing the piston
To fit the piston pin snap rings onto the piston pro-
ceed as follows:
- Use new pin snap rings.
- Prepare the specific tool.
Specific tooling
020166Y Tool for fitting the pin snap rings
NRG 50
Engine
ENG - 131