Looks like when running there is oil coming up from the head stud right in front of the spark plug. I just did a top end rebuild, everything seems to be good except this oil leak... The kit came with new studs an nuts....hard to tell in the photo, but I could watch it come up from the threads between the nut an stud while running. The drip down the front of the head thru the weep holes. Tried tightening a little more like a quater turn but don't want to go to much. Not sure where to go with this

 

Don't know the model at all but a glance at the parts drawing shows one head nut has a different washer under it to the other three. This usually means the "odd" washer has a seal on it, Dowty or copper as a rule. Torque head bolts to the correct setting, never more, there isn't much margin before you start to strip the aluminium threads and uneven tension can distort the head.

 

Honda ATV 2006 OEM Parts Diagram for CYLINDER HEAD | Partzilla.com

 

Like merryman said photo 10 is different than the 3 of photo 11 #10 is a sealing washer the others are plain washers under #10 washer is passage way the oil travels to oil cam and rockers

 

Well I got in contact with bpr which I got the kit thru, they suggested using the original cap but which sealed it up.....so I will keep an eye on it from here on out