Ok I have been thinking about this. I have seen where some others have thought about it but not seen where anyone has done it. I did see a crf150 with a xr200. I want lower maintenance motor in a better suspended bike. I have seen where guys are just upgrading the ttr suspension but I thought it would be fun and maybe I could get a lighter bike. So what questions should I be asking? What yz frame chassis should I be looking for? I have 04 forks on my bmw dakar so I would like to be able to swap wheels. What other years can fit the 04 forks Need to be a steel frame so I can do some welding. Could a 99 125 chassis work? What about the 250 chassis. Are they the same? What about the wr frame and chassis. Since I would like a light weight bike what frame and chassis are the lightest. About the engines in question. Xt225 Ttr225 And I really like the ttr250. It can be bored out to 325 but how much heavier is it. Thanks for all the help.