One of the problems that will develop in a big bore kit in an air-cooled engine is that there is less metal to help dissipate heat. The bigger cylinder means that there is more metal taken away to make sure that the rest of the cylinder stays the same size for packaging. Taida, however, has made it possible to get to more cubic centimeters out of your Zuma 125 without that risk, with the Taida Zuma 125 Water Cooled Engine Conversion Kit. This also increases the bore size to 66mm giving you a total of 198cc with the stock crank and 210cc with the 3.5mm stroker crank. The only things you need to procure are the radiator, hoses, and coolant.