The 50cc scooter is a VERY slow, low-powered machine. Nothing works like "cubic inches", i.e. a Big Bore Kit. A 4-stroke Kymco 50cc normally tops out at 28mph on flat land. With a BBK, cam, ignition, gears, and exhaust (the Kymco 50cc 4T is a Chinese gy6 engine) it will do 50mph. There's no cheap route to higher power. You can do it yourself for about $300 in parts, or simply buy a bigger scooter.