Polini Corsa 70cc Racing Cylinder Kit: Zuma, RH & Buddy 50

Mid-Race Performance: Polini Corsa 70cc Iron Cylinder Step up to "Mid-Race" power with the Polini Corsa Cylinder Kit . While based on the legendary Polini 70cc Sport, the Corsa is factory-tuned with revised port timing and a polished exhaust port to deliver significantly more horsepower and higher RPM ceilings. This cast-iron kit combines the bulletproof reliability of a daily driver with the aggressive acceleration required for the track. Technical Performance Features Factory Ported: Features hand-finished porting from Polini technicians to optimize scavenging and increase top-end power compared to the standard 70cc Sport kit. Thermal-Resistant Cast Iron: Provides a rugged, long-lasting bore that can be honed and oversized if needed, offering better durability for high-heat racing conditions. Chrome-Plated Piston Rings: Includes specialized high-tension rings designed to reduce friction and maintain a perfect seal at high crankshaft speeds. 10mm Wrist Pin: Engineered specifically for the standard 10mm small-end bearings found on horizontal Minarelli and Genuine 50cc engines. Comprehensive Fitment Guide This kit is designed for Horizontal Minarelli-based 2-Stroke engines. It is a direct-fit performance upgrade for: Brand Compatible 50cc 2-Stroke Models Genuine Scooter Co. Buddy 50, RoughHouse 50, Rattler 50, Black Jack 50 Yamaha Zuma 50 (2002-2011), Vino 50, Jog (Horizontal) Aprilia SR50 (Pre-2000 Minarelli Engine) Malaguti F12 Phantom, F15 Firefox Note: Not compatible with AF05E engines (pre-1994 model years). Technical Specifications Displacement: 70cc Bore Diameter: 47mm Wrist Pin Size: 10mm Material: Cast Iron Cylinder / Aluminum Piston Cooling: Air Cooled Mechanic's Note: The Corsa is a high-revving kit. To prevent engine failure, you must increase your oil-to-fuel ratio by adding 1oz of high-quality 2-stroke oil per gallon of gas. Additionally, this kit performs best when paired with at least a 17.5mm or 19.1mm Carburetor and a mid-race expansion chamber exhaust. Part Number: 1100-1486 Manufacturer: Polini Motori (Italy) Polini Corsa big bore (70cc) racing cylinder kit for Genuine Buddy 50, RoughHouse 50, and Rattler 50 scooters, Zuma 50 2T, and other horizontal Minarelli-based engines. Not compatible with AF05E engines (pre-1994 model years). NOTE: It's important to properly break in your big-bore kit for 200-300 miles before running your bike full throttle for any extended length of time. We also recommend adding one ounce of 2-stroke oil to your gas tank; 50cc oil injectors