PIAGGIO Beverly Tourer 125, Service Station Manual

Page: 119 / 278

zes. They are also classified into 4 categories A-
A, B-B, C-C, D-D.
Characteristic
cylinder: standard diameter
56.997 - 57.025 mm (at 41 mm)
Maximum allowable run-out:
0.05 mm
Inspecting the piston rings
Sealing rings
- Alternately insert the three sealing rings into the cylinder, in the area where it retains its original di-
ameter. Using the piston, insert the rings perpendicularly to the cylinder axis.
- Measure the opening (see figure) of the sealing rings using a feeler gauge.
- If any measurements are greater than specified, replace the piston rings.
N.B.
BEFORE REPLACING ONLY THE PISTON RINGS, ENSURE THAT THE CLEARANCE BETWEEN
THE PISTON RINGS AND THE PISTON RING GROOVES, AND BETWEEN THE PISTON AND THE
CYLINDER, IS AS SPECIFIED. IN ANY CASE, NEW PISTON RINGS USED IN COMBINATION WITH
A USED CYLINDER MAY HAVE DIFFERENT BEDDING CONDITIONS THAN THE STANDARD.
Characteristic
Top piston ring
Standard opening: 0.15 ÷ 0.30 mm
Middle piston ring
Standard opening: 0.10 ÷ 0.30 mm
scraper ring
Standard opening: 0.15 ÷ 0.35 mm
Beverly 125
Engine
ENG - 119