This topic has been covered many times in this forum, but I don't know how to direct you the previous posts. The main point is that the main restriction is in the maximum RPM permitted by the CDI unit. Unrestricted Chinese CDIs are cheap between $10-$20, including postage. There are two kinds of CDI: AC or DC. Most Kymcos are DC. If you install an AC unit by mistake, it will blow the main fuse. The wonderful feature of Communist Chinese technology is that all Chinese scooter parts fit all other Chinese scooters. It doesn't mean they're all the same, though! Some are for tiddling to the market, and others are for all out racing. But they're cheap and interchangeable. If you don't like one, buy another. It's awesome! BTW: in the attached photo, items B & C are too high performance and ratty to live with. "A" is my favorite, but there's dozens more models available.