I have one of those bikes, sorry to say it now broke down on me 3 days ago and I´ve had it since may 18th 2015. The idle is bad on it and it slows down when I get to 50mph. What do I do? And can I upgrad it, plz. Help will it be better one fixed with new exhaust on it and will I get 65 mph instead of 55 mph what it did.