Check your fan rpm and make sure you can go over 1000. The belt adjustment makes a big difference in top speed.
Try opening the bottom sieve more. Close the front of the top sieve to just let beans in. Set the top small rear sieve open enough to catch any whole pods before they go over the back end. The airflow on the old style fan is not as uniform and if the front of the top sieve is open to much junk can fall in and get trapped and not get blown out by the air. Also if the bottom sieve is closed to much it will slow the airflow to the top sieve where you need it to blow the hulls out.