I think the smoke is normal for the 5093. Mine smokes a lot when running at lower rpm's or lower loads. Clears up at full rpm under high load, but lets out an occasional puff here and there. It's been like that since brand new, very hard on fuel for the size of the tractor but i seem to get about the same consumption as it is rated for. I burn about 20L/hour running a moco, 10l/hr loader work. I don't think the John Deere engineers had efficiency in mind when the built the E's injection system, but I knew JD's were hard on fuel when I bought it.