Polini power Kit for air-cooled large scooters with 125-150cc Piaggio 3V 4-stroke engine with direct injection. 61 mm bore and 58.6 mm stroke means this aluminium cylinder kit has a whopping 171ccm displacement (compression ratio 11.2:1)! The cylinder can be used exclusively on fuel injection engines. The cylinder surface is hard chrome plated and the edges of the piston rings are also coated with chrome, to reduce the friction to a minimum. The control unit (ECU / P. 33230) as well as the corresponding cable set (P. 33231) are included. 100% made in Italy