I posted this on supermotojunkie.com but there seems to be some pretty smart people on here as well.
So my aforementioned bike has a random tick in the motor. Ever since I got it (at ~4000 Miles - I'm at ~9500 Miles) it had this tick at idle that was pretty random as though it wanted to stall but wouldn't. I turned up the idle a little bit and the tick all but went away. Over the weekend I replaced my blown base gasket and head gasket and when I put the motor back together I rolled it over slowly via the kick start and I got a very distinct knock on one of the strokes as though I had a valve sticking momentarily but then it would snap back to its seat and kick the rocker. I think that's the most logical diagnosis because I couldn't detect that the noise was caused by something hitting directly on the valve cover. I pulled the valve cover off again and the knock went away but came back as soon as I reinstalled it. Is this a known issue and should I be worried? I only run 91 or 94 octane gas but I noticed I had a bit more carbon on my piston than I thought there would be especially when you consider I'm running super lean. Now that I've got it all back together and running the tick is more often and doesn't go away with idle adjustment and stays audible while riding (city street speed) and still a bit random in that it's not a consistent 'tune' kind of like - tick....t-tick tick...ticktickity..tick.tick...tick..tick.