From what i understand changeing the smooth boss is the best first step towarxds derestricting as this will give you 38mph approx were as cutting the cdi first just leads to over reving and increased wear and tear. I really could do with extra few mph why riding round rural wales but my agility is running excelent starting firsrt time etc i dont know if i want to disturb or upset it at the moment done another 20 miles on it today and it never missed a beat.....