John
Guest
Wally, Most if not all the engine problems were fixed by the Series 3(1982). They have the 670I with the Ambac fuel system vs the 670HI with the Roosamaster system. The Ambac 670I was slowed down to the R series and the old 7080,7580,N6 (670HI engine)high RPM blow apart disappeared. I own an 82 N6 Series 3 and had the underhaul(rod bolts and bearings)put in at 3100hrs and it runs GREAT and the old bolts and bearings didn't show any trouble (but cheap insurance). I went from an M2 to the N6 and you will be very suprised in the capacity, and if you Hyperize it, you will increase the capacity more. If you are really worried about the engine, Cummins makes a nice retro-fit. I would be more concerned with other wear items with as much crop has gone through that machine, bars,cage,rolls,conveyors,augers. Rotaries work considerably faster thus more acres per hour thru the machine. But it is still an Excellent machine. Good luck!