Well, we run all our JC on diesel / jeta1 ( 70%/30% mixed ), but, i was used 100% diesel too, i think that the smoke that you have on you 140rx, is the oil mix ratio, on full diesel try 4% oil on fuel.
After many tests performed, for me, the best result on fuel mix is 70/30 diesel / jeta1, with 4,5% oil mix, to best : thrust, smoke, start and smooth running. All my engines have had 90 hs or more, after many inspections and bearing changes ( 50 to 70 hs run time ), the engines are absolutely perfect!!!
hope helps
jose