+1......pipe, headlight can be ditched for a lighter aftermarket one, that big ass tail section should go in the dumpster, plastic tank, etc.....you really can't get the DRZ down in weight too much, it's just an overweight bike.
^yah a full titanium pipe would help a bit. Honostly dont bother taking off rear footpegs, mirrors, or any other little randoms cuz yur just gonna add all that back on with hanguards, case saver etc. One thing that will make it feel lighter is revalving the suspension to yur weight. It will make you faster on and off road (if you take yur dizzer off road) but theres not much you can do to a 320 lb bike lol
iif you want your bike to feel lighter, hit the wheels. When I put a set of PVMs on my streetbike, it felt 100 lb lighter and handled amazing. Sumos are great because yu can ditch the heavy tubes and go tubeless with a little work and not too much $.
I weighed mine on a certified scale the other day, it was 300lbs ready to ride. That includes all the hand guards, rad guards, even a proper skid plate setup. Most of that weight was the exhaust and tail light setup as mentioned. The stock exhaust is ridiculous, it's a freaking boat anchor.
If you wanna get really silly and don't care about resale or passengers then not only the pegs but a large chunk of the subframe can get hacked off too. You can also convert to kickstart only and remove the starter. With no starter there's no need for a big battery so you could go with a smaller CCA lithium battery. Handguard case savers and skidplates can all be done ultralight as well so your not really adding that much back. If your mostly sumo on road then a carbon skidplate would prolly suffice. Personally I like the craigslist dirtbike swap idea but that deezers bulletproof motor is so tempting for the street.