For older models we are offering pistons up to 5. oversize (os). This gives you the possibility to freshen up your older cylinders. The bore Ø always includes the size of the cylinder.
Our first choice in piston stuff is METEOR. METEOR pistons are first class quality. In the PIAGGIO VINTAGE series, most of the pistons offered that are not made by PIAGGIO themselves is from GOL, Italy. GOL also offers oversizes in 0.2 mm steps. The quality is reliable.
Most pistons are outfitted with 2 normal piston rings (2xN) in 2.5 mm sizes (small frames 2.0 mm). With newer models, the upper piston ring is an L-piston ring. Older Vespas have baffled pistons, newer models have piston windows with curved piston floors.
SIP-TIP: install piston rings carefully, do not stretch too far, due to possible breakage. Pay attention to piston ring stop play, type and model. Trapeze rings have only one installation direction!
Handy equipment to make your cylinder work easier: Piston ring pliers BU5045, BUZZETTI gudgeon pin tool for installation/removal 15194000 and gudgeon pin chuck 17820000.