What's that in kernels per ft sq?
We typically run 5 or so kernels per ft sq and try to get less than that. Are the losses on the right side? If they are, open the bottom sieve to get less grain going up the return. If you've got whitecaps you've got to add filler plates to get them out. Trying to run them up the return and rethrashing them usually results in the grain going out the rotor.
After harvest, check your pinch point. Should be around the 10th or 11th bar down on the left side of the concave. Pull the middle one out, set the rotor in neutral and spin it by hand, bring up the concaves using a 1/2 in drive ratchet with 3/4in socket on the concave adjusting motor until it ticks. Wait till the rotor stops turning and check to see where the rotor contacts the concaves. Adjust it till the concaves side to side until it ticks at the 10 or 11 bar. Believe the book says bar 8, but that doesn't work for hard threshing wheat IMO.