I run an R-62 that I have done some mod.,feeder shocks,extra helicals,extended rotor bars,took out every second concave wire and took out reverse bars. Tried running rotor around 500 with concave open to about 6 - 8 ,but rotor loss in a light barley crop was 1 - 2 bus/acre. Got into some better barley (70bpa) and rotor loss went up (3-4, not 3/4) until I sped up the rotor to 900 and tightened concave up to 3 - 4. This then consumes more power,more fuel etc. Where did I screw up ?????