You and all your friends will love this:
I must buy a Yanmar Tractor
Re that JD850 appearance - this is an 'early' series YM240 with the hood hinged at the rear and headlights alongside the grill, not within it. About 1977. Its shape is closer to a Deere. Not much difference from the 'late' series YM240 aside from the sheet metal. There were four 'revision levels' and that is the first.
Eh? Winston? I can't hear you.
CarDoc's advice on PowerService is a good idea. But Friday I gave the YM240 a third dose of PS, now 50% over the 'premium' proportion, when the racket was getting to me during monotonous hours running the backhoe in one location. I'm not sure it helped. What does help is the HF Yellow $10 earmuffs that give real silence. Their two red versions aren't as effective.