Hi Red. Well What I say is only my opinion, and my climate and yeild may be different than yours. But, in wheat, if your tank sample looks nice and clean and seive loss is acceptable but you have rotor loss, then sometimes it could be as simple as cutting a little higher. But dont cut too high, I like some straw for the grain to rub against for threshing. Of course like you said, your wheat unfortunatly went down. One thing you might try is to run the machine at a specific rotor rpm drop and see if it helps. I would try letting the rotor rpm drop down about 50 to 60 rpm from the empty speed when you are cutting. Just watch the rotor tach and run the combine from it. that way you will have a steady load on the machine and can set it accordingly. The real only purpose of coverplates is to keep the grain from falling through the concaves too soon. If it falls through before it is finished threshing, then you will have excessive tailings and probably more white caps in the tank than you would like. On my machine in heavy 130 -150 bpa wheat, I like to run the whole first concave covered and the first half of the second. This way the grain has a chance to thresh completely and can then seperate more easily. I've never ran disrupters in wheat either. If you have the keystock grates you should have plenty room for seperation and should'nt need the disruptors soaking up power. In fact, in downed wheat you may wish to remove the smooth bean bars and reinstall your rasp bars. I'm not very well versed at the corn thing, so hopefully some else will post more on it. Also, there have been many post further down the page you might look at. But so far it sounds like you are on the right track. farm kid 2 has alot of experience with corn. look for some of his previous posts.