hi,went to set my s2 up as just rebuilt engine,found mixture on 0.2% managed to get it up to 1%,but found mixture screw not there and just some old threaded screw wound in there,i bought a second hand one a while ago and this has had the same treatment,was wondering if anyone else has had this problem,was thinking of getting a longer threaded srew and filing the end down to a point,bit crude i know but needs must.cheers