I used to tune 2 stroke 50cc scooters back when I was 16, since you have to be 18 to drive a car or motorcycle in Norway. Bought them stock with about 4.5 hp and restricted to 50 kmh. Changed EVERYTHING to racing parts and we used to end up with about 15 hp from 75 cc. And with 10 inch wheels you got your self a wheelie machine
Fun times, even had a switch on the bike to change the ECU between "road legal(ish)" with 3.5 hp and "not legal at all" in case the police stopped us to dyno the bikes..
Scooters are great fun, but if I had to pick something to commute on, I would choose something 4 stroke.. 125 vespa?