Last week I got my new mc18 but had some issues and here are the details: http://nsr250.net/forums/viewtopic.php?t=15043.
So one of the problems we found was that the idle rpm is around 1200 which is suggested by factory menu, but the bike died a couple times at low rpm idle without throttle, so we want to bump up idle to 1500 with a new pilot jet. The current pilot jet is a size 38 and we think it should be one size smaller.
So any place that we can get a new pilot jet?
Another problem we found was that the choke was kind of always on...fixed now.