Originally Posted by GeorgeinVA
To check you thermostat get a digital laser temp probe and read the oil cooler lines when the bike hits "normal" operating temp the lines should begin to warm. If they stay only a few deg above ambient temp. you have found your problem.
Hope this helps.
Or, if your fingers aren't completely severed from your sensory system: Touch it with your hand.
If should be hot as in "ooops". It will not be hot as in "funny smell - is that black thing my hand?".
I don't know on the 12GS, but on the 1150 (best model and all that) the oil starts to flow at three or four bars.
How hot the oil is? That is, in fact, a rather frequently asked question. And, luckily, you will find the
answer in the "GSpot FAQ".