I got my unrestricted boss for my agility from Taipai Scooter Assasins, delivery is slow at 1-2 weeks to the UK but it was only £8-£9. Gave me about 10-13mph gain. Race variator gave me another 7-10mph, and I use 5.5g weights. Also derestrict your cdi if the yup need it and its not been done yet. I get 50mph on a real good day, average 45-48 normally on flats.
If you search for derestrict yup 50 in the search bar there should be more info of exactly how to do it.