That is, photos of the bad thermostat I pulled out of my '05 last Sunday. Not stuck fully open but really stuck, can't budge it with hot/cold bath or as hard as I can force it with my fingers. Sure looks like the material of the heat motor body is incompatible with something in the coolant as it's pretty rough and cruddy looking. The rest of the body/springs look practically new.
BTW, somone was asking about orientation. You can see the offset in the stamping in the second photo. The orientation of the photo is the orientation of the 'stat in the bike, bleed hole to the top.
If I get really ambitious, I might dissect it to have a look at the innards:
I have the full res photos if anyone is interested in a really close look.
› Site Search for: Bad thermostat photos