Yes, I do have the correct concaves in place. I did have blanking plates on the front three sections of the rotors(i.e. half the rotor then). I thought that this might be part of the problem. And, I'm sure it may have helped a little but there is no way I would have gained 1.5mph in the field by taking them out. I put them in prior to harvest thinking I might be in some dry conditions. As mentioned, it didn't seem to matter how hard I threshed the grain. The settings only let you go to 8mm on the concave. I tried speeding the cylinder up to--if I remember correctly--900+ rpm. Thanks for you help.