I just did a head gasket job on my 06 just under 30k. I was on a trip in Baja. Running at sustaind triple digets for hours on end. Coolent started to puke on my right leg. I found a small amount of greyish slugs in my expantion tank. I re routed the over flow line into a coke bottle filled with water. So the over flow tube is submerged. Start bike, see bubbles? Head gasket blown!
I pulled the jugs and head and had them resurfaced, new rings and gaskets.
One cylinder defiantly had a low spot.
Good luck and have fun. The 950 motors are fun and easy to work on once out of bike.
06 KTM 950 ADV
2006 KTM 450 EXC
DMC FRAMED XR125