Just a quick note that may be important,
I have a RD250LC which was my learner bike, i had trouble with it using too much oil. I found that as the shaft of the oil pump wears, the standard oil pump chearance allows WAY too much oil in and i had to adjust it by feel to about 25 percent of the factory spec just to stop it smoking all the time.
It still left a cloud of smoke the length of the block every morning, but after that it cleard and only left the very light blue smoke after that.
I dont know if this will help at all but it may be worth checking.