The idle screw is an adjustment tomekzski, the further you wind it in the higher your idle.

 

It's not actually a choke on these bikes at all. Its a fuel enrichment circut so if it is on a quarter to half way it will cause your rpm's to skyrocket. It could be that or it could be the screw. Just back the screw out some with the pliers if its that. You probably need just one or two threads into the hole to have the idle set correctly. Just FYI if you can retap that hole for the screw without messing it up to much, the correct part with the screw and adjustment **** is only 10 bucks on partzilla.