Polini 70cc Cast Iron Cylinder Kit “Sport” Zuma, a very durable high-performance cast iron cylinder for everyday use. This kit is known for its impressive top speed considering the category it belongs to, and even more for its excellent performance at low and mid rpm range. The perfect cylinder if you want to pull wheelies! You’ll get appr. 9hp out of this kit. It can be used with the original carburetor. We now offer this cylinder in “Stage 1” trim, in house SSS ported, polished exhaust port, and chamfered. THIS kit uses BR8HS/BR9HS style plugs