Thank you so much for the recent posts! This is what I needed. I have a two port valve assembly, and it currently is plumbed to the bypass port for the input and the exhaust port for the return. Like I said, it's been that way for a long time. I can't believe the previous owners used it that way.
When I purchased this tractor, I got the original operators manual, parts manual, and the manual for the 1730 loader. I am pretty sure it was equipped with the loader when it was new because all three manuals appear to have been released in the same year (1979), and they look like they have been together from the beginning.
I just rebuilt one of the battery boxes today, and purchased new batteries for it. Looking forward to getting it all operating correctly (at least correctly from my point of view). Has anyone ever attempted to put a foot throttle on one of these? I plan on using this tractor with a bale grapple to load out hay and was thinking a it would be nice if it had a foot pedal to control the engine speed.
Thanks again for the great information!