Re: SHORT STRAW SIEVE OVERLOAD
Concaves should be fairly square on the leading corners of the crossbars -- if you rub your hand from the trailing side to the leading side, you'll feel resistance against your skin -- if you rub the opposite direction you should encounter about the same resistance. If resistance is absent, check for radiusing on the leading corners -- acceptable wear radius I'd recommend would be no more than about 2mm, and wear will be worst toward the center of the machine.
Buildup under thre rotor bar mounts usually isn't much of a problem, because it's usually fairly evenly distributed under all mounts.
In my opinion, your grate settings are good as long as they're in good repair.
Forgot, though, to mention the rear strippers on the rotors -- they have rounded corners and will slip (sometimes badly) thru the crop unless there's a buildup of MOG to provide traction (the MOG is pushing itself at this point). To alleviate most of this, we'll weld 1/4" X 1 1/2" wear strips to the strippers (flush with the top edge) in order to cover the corners and present a square edge for feeding. If you're having rotor hesitation (thumping and bumping) this sometimes helps quite a bit.