{"product_id":"evolution-iii-68cc-racing-cylinder-kit-47-6mm-bore","title":"Evolution III 68cc Racing Cylinder Kit, 47.6mm Bore","description":"The Polini Evolution III cylinder kit is a high-end racing component developed for maximum output on the track, intended exclusively for experienced riders. Built from aluminum with a nickel-silicon coating, it features a 47.6mm bore, a bridged exhaust port, and five transfer ports to optimize high-RPM performance. The kit includes a two-piece cylinder head with a central dome combustion chamber and a specific squish band design to mitigate detonation, alongside a gravity-cast high-silicon piston.\n\nThis kit is compatible with liquid-cooled Yamaha and Minarelli horizontal 50cc engines and is designed to fit without modifying original engine cases. To maintain engine integrity and prevent damage, the use of a reinforced racing crankshaft is strongly recommended. For a fully race-ready setup, it is intended to be paired with complementary components including a high-performance variator, exhaust, ignition, and carburetor.\n\nThis product is homologated for scooter racing championships and is designed solely for closed-course competition. It utilizes a 12mm piston pin and chromed cast iron S10 piston rings.","brand":"Polini","offers":[{"title":"Default Title","offer_id":52663286890808,"sku":"166.0113","price":375.66,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0970\/4895\/3144\/files\/687525794.jpg?v=1784325640","url":"https:\/\/store.motormia.co\/products\/evolution-iii-68cc-racing-cylinder-kit-47-6mm-bore","provider":"MOTORMIA","version":"1.0","type":"link"}