Hi, I have noticed a bit of a oil sweat (probably 2-3mm overhang from cover) on the exhaust side tappet cover. Is it something to be concerned about? What action should I take? Sorry, I have no to min. experience on engines. It's a XR650R. Thanks.

first you should clean it up good to see exactly where its coming from and check to make sure all the bolts are tight. If they are tight with it nice n clean you can keep an eye on it and first sigh of any oil youll know exactly where its at and can evaluate then. The minimal amount you described isnt really a big worry but i know alot dont want any leaks period. Worst case you would need to get a new gasket and take cover off and put a new gasket on. Nothing big just some time taking tank off and getting it off and cleaned up for new gasket.

If it's just from around the tappet cover, you probably only need a new rubber o-ring for it. :cheers: