yx150 w/v2 head leaks oil

mine used to do that a little. It was slowly dripping from the exhaust valve cover like you said. I just swapped out the gasket on the valve cover. The old gasket i replaced looked fine but it didn't do it any more once i replaced it.

I had the same problem but fixed it, if it leaks like it's coming out of the exhaust, take it off, call mike at tbparts, he is aware of the problem, I've dealt with him on that, the manifold stud holes often times can be drilled and tapped so deep that it makes a tiny hole near the cam lobe lube area of the head, I know you don't want to dissassemble, but ask mike for whatever parts you'd like him to donate for the inconvenienced time, he's super cool, and he'll do it, Plus r heads can do the same as well. My 2nd v2 head is perfect,

The early +R heads used to do that alot. Just pull the stud and use hi temp silicone on the end of the stud and install. Let dry and you are good to go.