Ever seen this before Grey?

[yam 3]

Here is the inside of a KX250F cylinder. It looks like a crack or maybe just an inperfection in the plating. You cannot really feel it with your fingernail. I am looking for input on whether or not it is useableThe marks are roughly in the same spot as the cylinder and water jacket meet...

Thanks

[grayracer513]

Too hard to tell from the pictures. The wear in the second shot looks pretty significant, though. I'd had someone check it in person.