Last year was my first year of farming so needless to say my combine experience is limited to say the least. The combine I am using is a 1976 IH 715. It performed fairly well, only a few minor problems. It also did a pretty good job harvesting the corn and soybeans. The problem is any speeds over about 3 MPH and the grain loss out the back was terribly excessive. 3 MPH and under was fine. My question is are there any adjustments I can make that will increase the ground speed without increasing grain loss? Thanks for any help.