Check the slide is in the right way cause 1 side it sits on the pin thing if its the wrong way around ive done it before lol. Also check that the cable isnt stuck under your tank or whatever
otherwise chekc your throttle adjustment is screwed out too far this happened to my mates bike today and we wondering why it was revving like crazy and wound it in and it was sweet
Checked cabel all good . throtel cable adjust looks good. then noticed that the carb spacer was in upside down .swaped it around and found spit o ring .fixed that and its all good .thanks gyes for the help