JD 45 -used it first time today

I used the 1966 model JD 45 combine today for the first time. Brought it home last Monday. Today I got it cleaned up and lubed so I went to the field to see what it would do. It ran good and the 25 bushels of corn in the tank was clean with no bits of cob or stalks. However, it was quite noticeable that there were broken kernels in it. An excessive amount, I don't know. How do you determine when broken kernels are excessive? Guy I bought it from had used it strictly for corn as he had another one for wheat and beans. The machine was set just as he used it for years. My moisture tester showed an average 13.9%. Corn had dried from 16% test earlier in the week. Does drier corn break kernels more? Will adjusting cylinder and concave clearance give less breakage? Guy had cylinder speed at 536 rpm. Operator's Manual says extremely dry corn will shell satisfactorily at 277 rpm . Using the standard sprockets with the machine I can get 386 rpm. This hybrid has very soft cobs and they were broken apart. I found no whole cobs. Is this indicative of too close setting of concave? Do you think a slower cylinder speed will reduce breakage of kernels? This corn will be sold to a feed production facility for nearly immediate use in feed, so does it really matter if there is excess broken kernels and fines? Any advice is appreciated. Thanks.

Open the concave until you have whole cobs. he size of cobs varies widely between different varieties of corn. Your cylinder MAYBE too fast but start out with getting whole cobs first. Then slow the cylinder down IF there is too much damage. The 386 RPM maybe better but I would not try to go down to the 277 RPM.

JD has it right.Open the cylinder wide open.if you get some unthreshed ears,close it a bit.Then slow down the cylinder.I ran a '65 45/313 cornhead for 10+ years,sold it this summer.They are good machines.Post a pic.Thanks.Steve