Couple ?s - '80 400 in an '81/82 monoshock frame?

[1980 KDX400-A2]

Hey, fellow KDX people - I've been a member for almost 2 years - it's about time for my 1st post. lol

I've had my '80 KDX 400 for 20+ years - I bought a giant basketcase of parts from a co-worker for $50 in the early '90s - consisting of most of a '75/76 KX400 and the KDX - close to complete, but in pieces.

Anywho - after MANY hours of work, I had the KDX running pretty well for a short time in the early/mid 90s, until I ran out of people to ride with. The power was most impressive for that era - although the only bike I could compare it with was my '76 KE125. No contest. Now, after the bike has sat dormant for 20+ years, I want to start riding it again before I'm too damn old to ride.

My questions after all the boring backstory are - will the 400 engine fit in an 81/82 monoshock frame? Is there any difference between the engine mounts of the 420/450 and the 400? I vaguely recall that the basic engine block is the same.

Is the 175/250 frame the same as the 420/450?

If that's all copacetic, all I have to do now is find a monoshock frame.

One more Q - IIRC, the petcock leaked, even after I replaced the o-ring. Has anyone discovered a functional, correct-fitting replacement petcock?

Thanks a lot for any help!

[KDXGarage]

Welcome to the forums and posting.

Good luck on getting back into it.

[NV Rider]

I don`t have any answers to your questions, but I`m sure one of the long time members will chime in. Good luck and nice getting to know your story:-) Got any pictures of the 400?

[1980 KDX400-A2]

I don`t have any answers to your questions, but I`m sure one of the long time members will chime in. Good luck and nice getting to know your story:-) Got any pictures of the 400?

Thanks!

I have photos somewhere around here - haven't seen 'em in a while. I'll post when I find them, or take some new ones.

[david]

I would try and find something later than a 175 frame to put it in. The shock in those is non-serviceable and most of the rear link components are not available anymore.

[1980 KDX400-A2]

I would try and find something later than a 175 frame to put it in. The shock in those is non-serviceable and most of the rear link components are not available anymore.

Thanks for the info - much appreciated.