How de-activate rpm/speed limit Vespa LXV 2v 125 4T AC 2006 Carb


I just bought an "almost new" Vespa LXV 125 2v 4T AC with Carburettor from 2006 with 1300km on board. From the beginning it was running 60km/h. After  buying and replacing from SIP the "Drive Tunning Kit Sport" - belt,sponge,clutch,spark...,main jet Naraku 96 and a visual check for other know form of limitation(intake,exaust...) it runs now 65km/h!!! - with almost the same without them. Very very disapointed :(

The speed and the accelation is the same with 1 or 2 passangers.

All my mechanics didn't guess where/what is the limitation...everything is new inside(~1300km) stock from factory excepting the ones mentionated.

Any hints, tips & tricks ?

Thanks in advance!