I got the technical manual for it. We did try a valve adjustment the other day with no luck.
Hour meter says 806 hours. But I'm uncertain if it works or not.
I recently bought a John Deere 950 with the Yanmar 3T90J diesel in it. Serial number tells me it's from the 1979/80s. It ran when I looked at it to buy it. Got it home and its ridiculously hard to start. Cleaned fuel filter & replaced fuel & did several other things. I won't go into long detail...