KDXRIDER.NET

I have an OEM KX250 expansion chamber, if I was to cut the head pipe section off and weld the head pipe section of my dented OEM KDX expansion chamber to the KX250 pipe, would it, (a) work, and (b) would I have some serious jetting/power issues?
thanks

It would "work" in a sense, but I'd bet your powerband would suffer. Different head pipe lengths can make engines run hotter(if some of the stories about 2 stroke yz250 pipes are true), and stinger lengths affect the range in which the power spread of the engine is most efficient. The two-stroke tuners handbook by Gordon Jennings is a great read for this stuff. I think it's no longer copyrighted and available on the net. If its not that one its another similar book by a different author. I have both books and I can't remember which one is public domain and which one i got on amazon. A lot on pipe design there.

Another useful book is DESIGN AND TUNING FOR MOTOCROSS by Jim Gianatsis. While this book is pre power valve technology, chapter 10 has much useful information on design of expansion chambers. For this, you will need to know the port timing of your engine, and the RPM you are tuning for.

It may be difficult to find this book on the retail market, but your local library should be able to find you a copy to read for a few weeks.