Join Date: Sep 2008
Location: Honolulu, HI, USA
Not immediately familiar with your bike, but note that you're in the "Mile-High City" altitude 5.000 feet so air is less dense and thus less able to carry away heat from the radiator. You've not posted your mechanical experience or aptitude so everything is negotiable, as it were.
Start simple: if the rad was drained, ensure it's refilled properly and no bubbles are trapped in the cooling system. You may have to do coolant system bleeding a couple times to get it right. Make sure there's coolant in there. Dumb things, but mission-critical.
There are the usual suspects to interrogate: if the bike overheats at a standstill, suspect the fan or clogging in the radiator. Does the fan come on when it should, and spin freely? Are the cooling fins of the radiator clean and not clogged with bugs or whatever?
If overheating occurs at speed, suspect the radiator. Can you remove and run water through the rad easily?
Possibly (unlikely, methinks) the thermostat is faulty. I doubt that.