Well if it's an engine from a TR97 you have to get pump rebuilt.   I had one fail about 10 years ago, NH said only 3 new ones available anywhere in North America.   No remans.   What you were supposed to do was send your old one to a place I think in Missouri to get rebuilt.

I couldn't wait that long so I had one of the ones available shipped overnight to us and installed.

A picture of the engine would be nice.