The - most probably very first - sparkplug change on my '03 XR4 required taking the head off, as the plug broke into the head - we have tried everything to get it moving, but it did not budge, just broke into 2. The thread was renewed, it's fine now, but inspecting around revealed the cam does show some ugly wear on one of the lobes. The engine runs and sounds great, valves, rockers and other parts of the cam are like new, engine has 8K kms on it. Should I worry, can a machine shop do something about this, or start thinking about a new cam sooner or later? Or just ride it and worry about something else. Thanks for the help fellows.