Originally Posted by Grinder
The black stuff is most likely ground up metal particles from the bearing itself. You most likely got dirt in it somehow. What type of bearing was it?
I only clean the carbon if it is really thick, and looks like it could flake off. I only clean the top of the piston. I don't clean carbon off the side of the piston. Carbon on the piston would not be your problem in this case.
Thanks for the tip Uriah. It was a stock, blue rubber sealed front steel bearing from nova. Had 1.5 liters since was last changed. Was in the flash3 you modded over a year ago, which has been a real Mad Max/Road Warrior type of engine! Thanks.