Hello guys, I rebuilt my 98 YZ250. After two hours ride(have hour meter) my cylinder looks like this from the exhaust port. The cylinder was replated and I'm using a new Wiseco piston. No scoring on the piston just on the cylinder wall. The top of the piston is clean(brownish). When I put everything together I washed out all the intake ports with brake cleaner. I also used compressed air to clean out all the ports. I installed brand new air filter. I cleaned the carb/rebuilt it. I washed the airbox. I haven't checked the compression yet. I will do it tomorrow. Sorry for the low quality pictures. I didn't have my DSLR on me. And it was dark in the garage so I didn't have any chance to make good quality pictures. I'll make some more tomorrow. Is my cylinder f...ed?