Quick anecdote that may, or may not, apply.
I was running down the highway, pulled into the weaving lane at the offramp and wound it up on a relatively new motor that was built with close tolerances. There was a very odd and somewhat violent miss on one of the cylinders nearing redline. Pulled in the clutch, and it stalled (actually it seized, unbeknownst to me). Downshift to 3rd, little chirp at the back tire and it's back to life. Baby'd it back home, it ran fine - maybe a little down on power.
A few weeks later, it started missing on one cylinder. Plug had a little oil on it. Not much, but enough. Checked it, and it was down 20lbs.
Tore it down. The piston, looked like this:
Hope that's not your problem.