HELP.. my 2004 YZ 250 has blown up, I have taken the cylinder off and the piston rings have broken, and the piston has cracked :-( . I have stripped it down and found that the cylinder has been bored out and sleeved and the cylinder is marked with the letter E.
I have measured the cylinder and the cylinder measures 66.35mm at the top and the centre measures 66.50mm and 66.40mm at the bottom.
What is the best meathod to repair, ideally not replacing the cylinder.
Are normal rings suitable for use with a sleeved cylinder.
Can I just put a replacement piston in?? What size??