PIAGGIO MSS Fly 50 4T User Manual

- The pistons are oversized due to cylinder rectifi-
cation and are subdivided into two categories 1st
and 2nd with 0.2-0.4mm oversize. They are also
classified into 4 categories A-A, B-B, C-C, D-D.
Inspecting the piston 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 thickness 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.
SEALING RINGS
Name
Description Dimensions Initials Quantity
Top piston ring 0.08 ÷ 0.20 mm 0.35 mm
Middle piston ring 0.05 ÷ 0.20 mm 0.30 mm
oil scraper 0.20 ÷ 0.70 mm 0.80 mm
MSS Fly 50 4T Engine
ENG - 89

PIAGGIO MSS Fly 50 4T Specifications

General

Brand	PIAGGIO
Model	MSS Fly 50 4T
Category	Scooter
Language	English