My Piaggio Quartz 50 from 1992. Got it broken, rebuilt the engine. Has probably over 25000km on it and now runs like a charm. For me it's the most fun and fastest
Ressort de contraste Polini Evo-slider pour Piaggio Quartz 50 2T eau | eBay
Fiche technique du scooter Piaggio Quartz 50cc - 50factory.com