Hello all, I am almost finished up with a deal on a John Deere 720 Diesel wide front, guy is reasonable on his pricing but its gonna need the usual tires repaint body work etc but both the pony motor and tractor start and run with no smoke. Now the only thing that is really holding me back from finalizing the deal is when he started it up it went to a irregular idle where it would idle up then down. I want to purchase it but I swore I would never purchase another tractor that needs to have the engine gone through, espically if its a diesel. Any advice or potential issues would be greatly appreciated..