Next step up from 75HP, Kubota requires DEF fluid. The one he got, has a procedure for cleaning out particulates from the exhaust system. When it calls for it to be run, takes about 25 minutes of following the procedures to comply with the program. I've done it once, PITA, but still better than pizzing around with DEF fluid? If you don't follow the procedures when called for, ya ain't getting any work done.
And yeah, the 25 yo NH turbo diesel was a start and get to fkn work machine. But we did all the work we could do with a rubber tired machine, so upgraded to a track machine. For no bigger/heavier than it is, it's a diggin' little bastard. It ain't the JD450E track loader I once ran for several years, but it will dig.
Dug enough shale with it last summer/early fall, already replaced the bucket teeth at 250 hours. OEM teeth weren't that bad, he's just a fussy old MFr.