John deere combine settings

[Pa85]

Hi
I have a new to me t660i and am struggling with high returns in both winter wheat and spring barley. What settings are people using for these crops, especially sieve settings.
TIA

 

[snipe]

11 to 12 on first little sieve. Top sieve 16. Bottom sieve 7. If going up any sort of hill I would open the bottom sieve up by 1 to stop it overloading the returns then put it back on the way down. Ran the fan at factory settings. Drum speed at at factory setting. Concave around 10. If you take the left hand cover off the side of the concave there is a handle inside to put the filler bars in the concave. A socket extension plugs into it from the out side. Always ran with then open. There should be a spare stationary rasp bar bolted under the feeder house. One is smooth and the other is rough. we always used the rough one, even in osr.