My local JD dealer has had issues with the injectors as well, his observation was to use only "fresh" diesel, purchased as needed, not in bulk and stored for any length of time (like a season's use).floridahay said:The local Deere dealer has had some problems with the 5 cylinder engines. They use electronically controlled injectors that are in the valve cover. Probably more efficient than the mechanical injectors but more expensive and trouble prone. The service manager said one tractor had problems with the injection system and the other was smoking badly and the engine was replaced, it was a new tractor. The 276 engine in the 5425 goes back to about 73 or 74 I think. It was first used in the 2630 tractors. It is in the 2640 that I have, it is a 78 model. It has had some changes over the years but I think it is still basically the same engine. I think that I would rather trust the 5425 myself.