Im with bret on this one, you don't know what condition the cylinder and piston are in. Pull it apart at look for piston smear over the rings or gouging of the cylinder. Piston smear = new piston, gouging = either a trip to the machine shop ( I'm with Greg on that one) ora diy home job ifits not that bad. You can get a break hone at kragen that will chuck into a drill.