ORIGINAL: WestCoastFlyer
Does your fingernail glide over the "scratches"? In other words, is this a slight marring or does your fingernail actually pick up the scratch?
If you can't feel the scratches with your fingernail don't worry about it.
I'm an engineering lab tech and can guess the scratches are 0.002" to 0.003" deep. I would have to pull the piston out to do the feel test, but yes, I would be able to feel the scratches using the fingernail method. Rotating the crank I can feel some sort of grinding/resistance through the stroke. Maybe I am being over anal for a $100 engine?