[KingElbear]

I know this is hot topic but im still new. I have a 04 CRF 250x mostly trail riding. I picked up this bike for a good deal few years back, and the maintenance is unknown on it. It runs good as far as I can tell but I did notice the valves are begging to walk about. I have never done any real work on it other than valve adjustment and oil changes. I see other people are putting 07 and 08 R heads on them. How does this compare to stock? I also fear it time for new piston and possibly a Jug. Should I stay with stock or size up. Or am I just putting lipstick on a pig? This will also be my first top end job performed by me and my son as are attempting to learn together. so feel free to over elaborate.

[Leardriver]

You can leave the stock head on it, just have a shop cut the valve seats, and put stainless steel valves in it and an R cam. Of course, a new piston and rings. It isn't too tough, and you will like the peppier performance.

[KingElbear]

isn't the copper guides the real issue with with heads? Does it cost more to redo the guides than the a new head?