I've had the valve cover off and on my 2008 KX 450F about 27 times now and cannot get that stupid o-ring to fit (the one with the "G" by it in the exploded view)!!! I bought a new spark plug hole gasket and o-ring, but every time I torque down the valve cover some of that o-ring plops into the spark plug hole. I finally pulled the o-ring out and just torqued it down with the spark plug hole gasket. It still leaks a tiny bit of oil I think, but at least it's not squirting out the spark plug drain hole onto the headpipe. This thing is driving me nuts!!!! How do you get the o-ring to fit under the spark plug hole gasket? Unfortunately I didn't have the advantage of pulling it apart the first time (the incompetent dealer did it). I'm hoping I'm missing something here and trying to put the o-ring in a place it's not supposed to be. HELP!!!