just derestrict it, i got a gilera dna got derestricted well partially last week, had this plate removed from the carb it used to go around 32 mph on a flat now i get about 43 on a flat and i can really tell difference before it used to struggle up a hill now its just fine. tomorow hopefully will remove washers and that should give me and extra 10mph. fuck the law i think 30mph is more dangerous than 45mph, cars take the piss when u can only go 30 a little speed can get you out of trouble at times. but i think ure better off derestricting at that point you wont even needs a sports exhaust.
the older pipes were ok derestricted, the new ones REALLY dont rev ATALL. need atleast a piaggio expantion chamber (like all the dna's) or a sports pipe. sports pipe is cheaper usually.