Originally Posted by nachtflug
someone remarked it looked like a works bike but it looks like a stocker to me. KX400 by the looks of it. Jug is too big for a 250. Pipe is stock in its routing but definitely new hand made pipe. The first KX's were pretty decent, my cousin had a 73-250 that ripped pretty good, but again, the Elsinores were a little better and their sheer numbers in riders on the starting line gave them that much of an extra edge. But the KX's were good. Fast and light.
I was very surprised at the number of this vintage KX (1973-75 ish) at the Mid Ohio Vintage Days MX this past summer. The guys I chatted with claimed parts were easy to find and cheap. There were a lot of them there and going pretty good to boot.
The KX 400 was the runt of the litter in that most people running in the open class were still running European bikes with the odd Suzuki or Yamaha thrown in.
But this could be a works bike, its hard to tell. My money is on stock KX 400.
This is a stock 1975 KX400 with aftermarket shocks and fork boots. Judging by the amount of fork travel, I would guess it has a fork kit installed as well.