The main thing is to change the gear ratio at the rear of your variator case. Your scooter is rpm limited and will only go so fast unless you can get more rpm out of the rear (drive) wheel. Most 50cc scoots are limited by European law to 50kph (~30mph). It's against the law in Europe to upgrade the speed limit. In other places you can get away with upgrading. After changing your gear ratio ($60 online purchase + assembly) you can install a BB kit which will give you the extra power to drive the new gear set. You don't need to do much more than that. If you're lucky, and the gods are smiling on you, you might get 70kph out of it. It's way easier, maybe even cheaper, to buy a bigger scooter - a 125cc scoot will easily do 90kph (55mph) without even breathing hard.
