Combines 760

They don't all do it, and it could be any number of problems. It could be the condition of your cylinder bars and concave, or the setting of your concave. One thing I've found is that if you follow the recommeded settings you'll be surprised at how much barley you can stuff in a 760_860, and if you don't push it hard enough you'll actually send more barley out with the straw than if you push it too hard.

My concave and rub bars do show some wear. How do you tell when it is time to replace themIJ As far as settings go, I tried the factory setting and then increased the speed to as much as 1000rpm and decreased it to about 825 with no real change in carry over. I also tightened up the back and the front of the concave alittle more. Is there anything else I could doIJ

If the heads on the rub bar bolts are getting round it's time to replace them

you could speed the fan up, or open up the seives