Mine is an X50/3 3 speed handlebar shift. Many of these were made as MOFAs 30km/hr (18mph) restricted to avoid the high euro taxes on faster vehicles. Mine was a MOFA. The case was made smaller so you could not put a regular Puch cylinder on it. I got a 50 kit and honed the skirt to make it work, added a chamber and a 14.14 and voila! 38mph and wheelie poppin