Currently cutting soybeans with 9770 and 35' macdon. I have rpr concaves in with 2 cover plates on. Combine had been having very little grain loss and was horsepower limited. Now I am in 80+ bu beans with green stems and am having rotor loss if I get over 3mph. I have concave at 23, rotor usually 600 but have tried 550-680. Fan 1050, Chaffer 18, sieve 12. No shoe loss and sample ok. What speed should I run rotor to help? Is concave ok? I may be at the machine's separating limits with crop conditions but would like to be as productive as can without sacrificing losses.