According to my measurements, these are the weights with an empty fuel tank, but otherwise ready to ride:
Stock '91 DR250S = 291
Stock '98 DR350 = 258
My finished bike* = 267
The reason my bike weighs more than the DR350 is the increased electronics (stator, rectifier, etc), and other things I've installed like heavy duty hand guards, tool pouches, tools, tubes...
* really, I'll probably never be finished with this bike. Next on the list is rear suspension work. Even with the front suspension work I've done, it's still lacking. There might be a set of USDs in this bike's future. I think next winter I'd like to cut off the steel rear subframe and fab an aluminum one to decrease weight. And there are more things I have in mind as well.