2003-1990 KX-DX Hybrid Build

[diamonddom]

Help needed on KDX250F1 SR 1991 recently purchased this bike, Jap import engine number DX250 F1 - 000054.
One of the first produced maybe? I want to know the differences between this engine and the KX models 91 - 94.
Is the stoke different? Is the crank shaft different in any way.
I will be doing a rebuild and have a donner 1992 KX250 engine that is already stripped. I want to do all the machining, cylinder re-bore etc and then transfur parts over to KDX bottom end.
Has anyone done this, are there any problems I might face?
Thanks Dom

[jprischak]

Hello, first off want to say all this is a great help. I am planning on doing a very similar build with the same engine and frame setup. You said you used a pro circuit exhaust, what engine and year is the exhaust from? I saw that you said your muffler was from a kx250 wasn't sure if the exhaust was the same.

Thanks in advance.

[dfeckel]

The pipe is for an H series KDX 200. It did require a little modification of the angle of the stinger. I chose the Pro Circuit because I thought it had the best chance of needing no mods to work on my setup. Because I used an E series motor, it needed a bunch of modding to work. If you're using an h series motor, then I bet it will work with almost no mods. Good luck!