I doubt that it will hurt anything, it's a graphite lubricant which Honda apparently used an abundance of in the earlier oil.
I almost junked an 811 engine because it was so black inside, I thought it was carbon from the plugged exhaust it had when I got it. A percentage of it may have been carbon, I don't know. It's been under the bench for years and when Mark mentioned that oil, the little light bulb over my head lit up.