I run a 2188 w/ 30ft. head in wheat. This past summer the wheat was 60-90 bpa and it seems to me that i didn't have enough capacity. It wanted to throw wheat out the back(sieve loss) with any speed over 2.5MPH. Is this normal? Hear and see guys put 36' on and going faster! I had front two concaves OEM small wire, third larger wire and key stock grates. 1 5/8 top sieve. Any suggestions or is that all i can expect? We do have a open slat sieve we use in beans and corn, can i use that in wheat? Mechanic says i won't be able to clean the wheat up good enough?