i am new to mx, just got a 2002 yz250. everyone selling a bike (including the previous owner of my bike) says that is has a fresh top end. i have read a lot of threads here that say the first thing you should do is check and/or replace the top end because it is cheap insurance. i pulled the jug off yesterday, the piston is in great condition and the rings are within spec. the thing i noticed is that the cylinder has been sleeved. it is in good shape now, but if in the future if it does get scored then what?? are sleeves plated?? if so can you get them replated?? what are my options??