how to fix carburetta on 2 stroke honda sky 1997?

I have a Honda sky 50 1997 2 stroke I have put a 70 bore kit on it it struggled so I read big bore box and said up the main jet in carburetta I had a 72 in so bought 90 to 108 and placed a 90 in first no different so placed a 108 in no difference runs but mixture screw and idle screw do nothing when altered doesent like filter on anymore runs fast without on with filter on loads of petrol when took off runs cack then picks up when burnt slight petrol please help