^^Agreed. I know going into anything for the first time, chances are likely I'm going to make mistakes. But for better or worse, that doesn't usually stop me, haha. This was a good learning experience, especially being I had put off this valve adjustment for much too long just out of pure intimidation, despite having done plenty with suspension, carbs, and other eternal components in the past. I'm glad this was on a ninja 250 and not an expensive bike. I actually won't be afraid to do this again in the future now that I know what to be careful of....
Doubly so because- with much penetrating oil, a slew of different pick like tools, and even more coercion and struggling- I managed to unwedge the piece of metal! Frabjous day!
The metal piece was off the end of the cam shaft itself. Not 100% certain why one shaft failed while the other was fine under the same stresses (I maintain that the cams are made of seriously brittle and fragile metal, though), but I'm assuming the piece chipped off when I loosened the cylinder cap before loosening the chain guard brace, causing it to somehow lever itself against the engine case and break off a small piece. Having never opened my own engine before, I didn't bat an eye at having two slightly different shaped ends, as the chip was so clean, and I didn't know what to look for. Which still seems odd to me, since the cams both came out so uneventfully, but unless it had been starting to fail or running like that previously (which I assume wasn't the case), that's the only explanation I can think of for when the piece got jammed in there
So new tip for anyone else who might try this for the first time and is as awkward as I am: Also be sure to loosen in perfect sequence to prevent possible leverage. Or suffer the tiff-tastic consequences
Not a great shot but- Pic: