I'm looking for a little bit of advice on 650GS twin for replacing the o-rings that are under the camshaft bearing cap. I went to help my friend change the spark plugs on his 09 F650GS twin last night. It's got 58,000 miles on it and when I pulled the #1 coil stick out there was oil all the way up to the top of the spark plug on that cylinder. The #2 cylinder was dry. I checked the valve clearances while we where in there but figured it's either the o rings under the camshaft bearing cap or the center valve cover gasket leaking oil into the #1 spark plug hole. I've never had to pull the camshaft bearing cap since the valve clearances on my 09 F800GS have always been in spec and same for his bike as well. Looks fairly straight forward from the repair manual. What do you guys use to lock the crankshaft at TDC? Any need to remove the cam chain tensioner? Here's a picture of the oil in the #1 spark plug hole. Thanks!