Wookie - On mine the gasket may have failed in the area between the main stud and the smaller bolt, and the oil is then finding its way out through the bolt hole. That 6mm bolt felt like it was going to strip the threads so I may not have torqued it enough. I'll find out the cause when I swap the original head back on, I changed heads years ago to add some heli coils to some of the cam bearing cap holes. (then never got around to the repair, cuz the bike ran good) When I put the original head back on I'll repair that 6mm hole in the cylinder also. I'm guessing someone before me may have had their forearm set for the same torque as the main stud nuts when they tightened the 6mm bolts.
