I bought a 2002 CR250 off an occasional rider, never had anything done to it and runs perfect. 4 desert trips last season with no problem. I want to put a top end in just to be careful. Should I buy the Weisco complete kit or just a piston and rings. I know I need to see how things look , just curiuos if a piston and rings without wrist pin and bearings is usually ok. Thanks in advance