Not real sure what the problem is here, you might check to see that your corn head is not stripping the kernals off the cob. On our 1680 we always get some kernals coming back out of the throat but its not a real big problem. Do you have the little 3" by 4' (roughly) canvas that bolts to the front of the throat it is supposed to keep grain from coming back out into the head. You might take off the access panel that goes to the front of the rotor and make sure that theres nothing wrong. Good luck! Brad NC. IN.