Same up NE sask super dry brittle straw, nothing to do but put it all through the grate, pull some more helicals out of the seperator grate, your sure its rotor loss though, I was loosing out the rotor but was also overloading the left had side of the shoe which on the ground looked like rotor, more wind less helicals more rpms on the clinder helped me, real low now and even better at night when the straw toughens up (the little it does I mean it is DRY here!)