Check that your hay dog springs are working properly. Two up top, one in the bottom of the chamber. Then check that your wedges are not flattened against the sides of the chamber. Then see how worn your feeder tines are, and the spring that holds the third set on the end is workiing right. Start out by setting them where the original factory paint marks are.
Then see if your hay flap at the top at the entrance of the hay from the pickup to the plunger chamber is there. Then of course there's checking to see if your plunger clearances are set right, both side to side and top of the chamber. Run at a speed so the plunger cycles about once per second.
Make big windrows, and fill the maw of that baby up when making bales. If all those things are correct, the 68 makes a fine bale, though you won't make much time with it. 7000 twine works best for me.
I got one out of the weeds a few years ago, took me a season or so to work the kinks out, but it works great now.