Has anyone else put anXR engine in a KAW KX frame?

OnAnySunday

Big Pig
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Nov 20, 2000
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lost in the deserts of NM
I've never tried it personally, but i saw a good example of an engine swap at a dualsport ride a few years ago.
Guy had a Kawasaki KLX250 -w- a XL600R engine in it!!
Talk about a "sleeper"!!! :eek:
I have no idea how he squeezed that engine into that little bike.
 

Jon K.

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Mar 26, 2001
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I put a 200 XR engine in a KDX200 frame once upon a time and the carb ran right into the frame! Bummer!

Ended up bolting the carb directly to the engine ( with an insulating plate between...some sort of plastic goppy that came on some 200 models) and ran a long airfilter boot back to the airbox.

Worked great, but never again!! I must have had a couple hundred hours in that infernal machine!
 

yam314

Member
Apr 17, 2001
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Yea, I have been to the SoCal site-thanks.I have managed to get the carb to fit by extensively modifying the frame and using a different tank,but need some tips on a different style airboot so that I can use the stock airbox.
Jeff
 

Jon K.

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Mar 26, 2001
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Not seeing exactly what you are up against, I can only advise what I did on mine.

Found a piece of radiator hose the right diameter and ran it back THROUGH the wall of the airbox. The hose I used was factory bent 90degrees where it went through the right side of the airbox. I was then able to clamp a universal filter directly to the outside dimension of the hose (inside the box). Worked great! I don't remember if I had to stiffen the hose where the filter clamped down, seems like it was strong enough as is.

Good luck!
 

yam314

Member
Apr 17, 2001
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I was thinking about doing the same thing.Did you remove the boot altogether and put a plate w/ a hole in it?How did you seal it all up?I was wondering if another type of boot would work in its place.What style of exhaust did you use?

Thanks,
Jeff
 

CRGuy

Posts Too Much
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Nov 14, 2000
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You guy's sound like BBR or something. But instead of using Honda and Yamaha you guy's are Kawi and Honda. Try using the KX80's boot and filter equipment. Maybe a set of tube's, Well a snake of tube's could aline it well enough. If you can get A TTR-90 tube that connect's the Carb and airbox that might help for bend's.
CRG
 

DualSportr

Member
Aug 22, 2000
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You might check with Cartwrights Conversions in Dallas Texas (I don't have his number, but you can look it up in the online yellow pages).

He has done quite a few of the KX/XR conversions.

I believe he uses a hand built aluminum plenum chamber from the airbox to the carb.
 

Jon K.

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Mar 26, 2001
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The original air boot location was useless for my application. I sealed it up with an aluminum plate pop-riveted over the original hole. I then took a holesaw and cut a hole where I needed it, just big enough to pass the radiator hose through. I got a good enough fit that I didn't need any sealer where the radiator hose passed through the wall of the airbox.

The pipe was a nightmare. I actually tunneled through the existing airbox and replaced the removed material with another piece of aluminum formed around where the pipe passed. The airfilter ran pretty high in the airbox so I had room to do this.
I had to turn the shock around so that the integral resevoir was on the left side. The pipe passed through the right side of the airbox and where the resevoir was.

Never again! What I was trying to build was a lightweight, well suspended four-stroke. Today you can go down to the Yamaha store and buy EXACTLY what I spent hundreds of hours trying to do. Only better!! I have GOT to get me one of them YZ250Fs.

Happy trails.
 

yam314

Member
Apr 17, 2001
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0
WFO,yea, I probably should have bought a TTR,but then it would be just like everybdy elses TTR.Anyway, theres no turning back now.Your idea about the airbox plate sounds like it might work.I'm thinling that maybe there is an airboot off of another bike loike the TTR or CR80 that would work.The problem w/ the KX's airboot is that it points downward and when you bend it up to meet the carb ,it is severely kinked.I'll give John Cartwright a call also.
This little bike should be really neat once it's finished.I'll use it to ride w/ my 6yr old on his KTM50.My WR400 is just no fun to ride slow.
Jeff
 

Jon K.

~SPONSOR~
Mar 26, 2001
1,354
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yam314; Please don't misinterpret my meaning; I do not regret building the machine; I even raced it and won a championship!

But having done it, I can safely sit back and say with certainty "never again!"

Project bikes can be quite rewarding in unexpected ways, but gee-niminy Pete, they can take their toll on the builder!

Have fun with it!
 
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