I got a 1989 CR500 in a '06 crf250 beer can that I recently replaced the header o rings on and took a look at the cylinder. It runs great, doesn't feel down on power at all. I see no signs of detonation, the piston wash looks good but I see some dark lines on the wall. The hatching still looks good but these are concerning. They don't seem deep at all but I thought I would ask what you guys think?
I'm not sure if it is just how close the picture was taken but it looks rougher than I am used to seeing but I don't look at them through a magnifying glass and that may be the perspective these pictures were taken. I can see cross hatching for sure but they look kind of ball hone style deep...may just be the picture.
It's the cylinder side of the bridge you need to look at. The bridge is supposed to have a bit more clearance than the rest of the cylinder since it gets hotter and experiences different thermal expansion.
