NCY Yamaha Zuma125 59mm Cast Iron Cylinder w/o head 
Give your Yamaha Zuma 125 some extra kick with this bolt on 158cc big bore kit.  Don't forget that unlike most scooters, the Yamaha Zuma 125 is a Fuel Injected Scooter, and in order to get this cylinder kit to perform properly, you must purchase a Fuel Injection Module.  We recommend the Two Brothers Juice Box.  You can purchase the juice box here:  http://www.twobros.com/cgi-bin/shopper?preadd=action&key=008-247
You'll definitely want to check out our Crank Case Breather specifically for your Zuma 125.  If you're adding a big-bore cylinder kit to your bike, or you ride at high RPM, this is a must-have!
Not legal for use in California on pollution controlled vehicles.  Check local laws before installing.