Just got this bike, the engine made a strange pinging noise when I turned it over, so I pulled the head and cylinder to have a look. The cylinder still has it's cross hatch and the piston is almost perfect. This thing does not even look broken in, really. I still don't know where the pinging noise is coming from and it's not the piston tapping the head, I checked.
It might be a little hard to see, but the piston seems to have a notch taken out of it right above the ring pin. There are absolutely no scores in the cylinder and I read 120PSI with a tester. No idea what happened here.
Anyone have an opinion on how bad this is?