I thought I would post this up just incase someone else is replacing their thermostat. Mine (08 SDR) developed a slight leak where the 2 halves screw together. On disassembly the O rings were all fouled up with the back sandy crap. I also found that the post the thermostat valve rides on had actually punched its way through the little stirrup of sheet metal that retains it on the rad side! So new thermostat and the point of the story. KTM only sells it as a unit, thermostat and housing. Got a new one, installed and as soon as I filled the system it started leaking at the seam. Warrantied for a new one with much cursing. Installed the new one and same leak. This time I took the housing apart and found there was only one O ring inside. The one outlet side that goes to the rad was missing its O ring. Luckily I had saved the O rings from the original so I pop one in and no leaks. I don't know how widespread this might be but it was 2 for 2 with me. So it looks like somebody in Austria sucks at their job. Anyway if your new one leaks take a look inside. Oh and my bike runs a lot cooler with a thermostat that opens all the way!