Hi Rob, It is a few years since I had to work on IH knotters but if I understand you correctly, if you spin the knotter trip wheel until it reaches the trip position and then if you turn the flywheel in the correct direction the knotters will not trip and do a tie cycle? Is that correct?
The assembly is called the "bale length control" and it is shown at caseih.com parts at:
There ar a couple of springs involve, 1 to cause the dog to trip and the other to return the bale control lever to beginning of bale again.
I suspect you accidentally knocked off the trip spring or the mechanism is frozen up with dirt and may require cleaning or lubing with your favourite penetrating oil.