Fitting Sports rollers?

I have recently brought a moped, a 50cc peugeot speedfight 2, i have friends that have scooters and they are all much faster than mine, i hve searched the internet for sport bearings and am wondering wether that is the best thing for making my moped abit faster, I am not sure wether it is D-restricted but i have been looking on this site and have already d-restricted my sports exhaust from instructions on here, i am wondering are there any other ways of making my scooter go faster i.e Buying a new air filter, new bearings etc please could you write back with your reccomendations thanks alot.