Hey all. I have a chance to pick up a honda nx250 for cheap, which I was thinking of taking down to south america.

Just wondering if anybody had any experience with this model bike, if it's easy to work on, reliable, and if spares are readily available for it. Also, how does it perform on/off the road?

Any and all input is welcome. Thanks!

As far as I remember, the NX250 is a smaller version of the venerable NX650 Honda Dominator. It didn't really sell much in Europe as Honda decided to strenghen the engine internals with top quality metals and, as such, the price was silly.
However, this should mean you are getting a very, very strong little engine in a powerful frame. I know of a Danish couple who toured either Africa/S.America or Russia on the NX250, and they were full of praise for it. It is very light compared to other bikes, so far easier to handle off-road. No doubt very frugal, too. If you have found a decent one, it should be an excellent bike.
The negatives? You may, as you wrote, find spares hard to come by. Maybe there are some owner's sites out there with good information on this? As a single cylinder, air cooled engine, you shouldn't need too many spares to worry about.I'm sure the bike was sold in Germany, too. Try some German spares/bike dealers for quotes on prices ( nearly always outrageous with Honda ) and availability.
It may struggle to maintain a high cruising speed and need a lot of road for overtaking, but hey - you are on holiday, right?!!

this bike is my favorite!

have been travelling tough roads with this extremely light, small and economic bike. algeria (hoggar south, b.o.d to illizi), south america (for example: uyuni to san pedro / pictures here) and morocco (taouz-mhamid etc.) - no problems so far...
the small size of the bike gives you full control even in dangerous terrain. with a "white power" rear shock absorber you will be ready for any challenge, even with lots of stuff (the original absorber is the one weak part of the bike). the fuel comsumption of 3-3,5 l /100km saves a lot of money and logistics while travelling long and "dry" roads.
the honda nx 250 is extremely reliable - my south american one is looking back on 110000 km. there has been no breakdown, no mechanical problem - nothing.
this bike is cheap in germany (built until 95), and - because it is a favorite by women - usually in perfect condition.
you will need the original 20kw for sandy deserts, most of the older ones have full power.
one problem are the tires. the front one lasts about 35000km, so no problem here. but the rear one (120-90/16) is virtually not available in poorer countries. worse than that, life expectance of both available products adds to only about 10000km. so bring along two, if you're going a long way from home!

with a bike like this i'm sure you will share my travel experience:
half cost - double fun!

good luck to everyone