Ok so I recently wanted to speed up my scooter a bit from 50kph max so I ordered some variator rollers. Everything was fine and I installed them however when I tried to turn on my scooter, things weren't normal. There was a bit of a rattle to start off but then it wouldn't work well. I tried driving it but once it reached around 5-10kph it felt like the rear brake was coming on? It was almost like it couldn't speed up and the brake was always slowing it down. I also fiddled with the carburettor fuel air mix but I don't think its that as I have changed it before. I even tried using my old rollers however the problem persists I really need help as I now have no transport