Hi. ive just blown my speedfight 100cc agen, and i have to get a new bike pretty quick. im gna have to get a 50cc tho because im only 16 (dont ask y i was driving a 100cc) ive seen a Suzuki TR 50 (street magic) for £350... i had a little go on it and it seem fukin quick. but it flattens out at 30mph as it is restricted. are these bikes derestrictable. and if so. how?