we had that model something like 35 yrs ago so my memory is foggy. One day we hit a big wad of damp hay and twisted the driveshaft that goes from the flywheel to the knotter area like a piece of licorice. To put the new one on we ran the plunger in as far as it would go and turned the fork that pulls hay into chamber and knotters to top dead centre. I believe we turned the pto shaft with a bar to make sure that nothing was going to bang into each other for a cycle or two. I would think that then when the tripper signals that the bale is long enough the rest should cycle properly.