KX 200 - KDX/KX Hybrid

[Svock]

Hello,

I have been off the forum for a while, but I am back, and I have pictures of my hybrid. It is a 1997 KX 125 chassis, with a 1996 KDX 200 engine in it! It is the best bike I have ever owned. My goal for it was for it to ride as nice as a WR250F. It blows the WR away now!! I can't ride anything else. It is so light, and easy to ride, yet it has plenty of power, and GREAT suspension. I highly recomend this conversion to EVERYONE. I will be more than happy to answer any questions you may have about it. Please feel free to ask. I will also post some pictures of it.

Svock

 

[Svock]

Here are the front and lower engine mount pictures...

 

[Svock]

Here are the pipe mount pictures....

 

[Svock]

Finally, here is a shot of the airbox, where I mounted some electronics, and a shot of the forks, with new graphics on one fork guard.

 

[kx200]

That’s why I still race my 89/1994 kx200 it works so good! I had a Gas Gas 250 that was close but it was not as reliable, and the gear ratios were to close. My 2003 wr250 is for sale.Thanks Jeff for building a great bike.

 

[BucKat]

Thanks for the pics.

Welcome to the club.

Buc

 

[boybagsek]

i plan to install a 1993 kdx 250 motor on a 1993 kx 125 frame. will it fit? i'll be using the kdx swing arm, tank, forks, triple clamps, etc. the only thing i'll get from the kx is the frame. appreciate all the help i can get.

 

[placelast]

Good Job! It looks almost as nice as mine (j/k):

http://i39.photobucket.com/albums/e195/placelast/027_23A.jpg

http://i39.photobucket.com/albums/e195/placelast/026_22A.jpg

http://i39.photobucket.com/albums/e195/placelast/025_21A.jpg

Mine has this electric power from the bottom to the top; great for knarley singletrack, light and very flickable compared to my 250, but doesn't have the I-dare-you-to-twist-the-right-handle power, so it'll eventually go when I pare down here soon.

 

[Rog]

I had an 89 kx125 with an air cooled kdx200 motor about 4 years ago. Wish I had never sold it. I' v just come across a complete rolling kx125 frame and was thinking I could make another one. I never really took much notice of my old one but was wondering how easy the motor slotted in and were there any major mods to do to get it to fit. The old one just looked like it was made like that from the factory. Do any of you guys know?

 

[pete fry]

Nice conversion what pipe and silencer did you use??

 

[mark_england]

i put a kdx motor in a 99 kx frame the tail end of last year,, [was featured in the UK Trail Bike magazine ]

turned out pretty nice.

im currently working on a wr200 motor in a 2001 yz125 frame [complete with ohlins shock, ally tank and titanium subframe]

after that im gonna do another kx/kdx

 

[b1dude]

SVock...nice hybrid. A question for you now that you have it running.

Some background: I took a different approach on my KDX by just doing the front end conversion. I put a 95 KX250 fork on the front. I like the handling difference.

My question for you, now that you've had a KX apart right next to a KDX....what are the biggest differences besides gas tank size between the two setups. One of the biggest critiques of our KDX's by the magazines is that the KDX is heavy compared to the competition (KTM 200, etc.). What major components (frame, swingarm, etc.)are the biggest offenders of the "overweight" sin?

I've started wondering what I could do to my USD forked KDX to put it on a "diet" and bring it's weight down to something similiar to you hybrid. Curious what your experience with your hybrid would point to for areas to target for weight reduction.

Thanks,

Eric

 

[adam728]

My question for you, now that you've had a KX apart right next to a KDX....what are the biggest differences besides gas tank size between the two setups. One of the biggest critiques of our KDX's by the magazines is that the KDX is heavy compared to the competition (KTM 200, etc.). What major components (frame, swingarm, etc.)are the biggest offenders of the "overweight" sin?

I've started wondering what I could do to my USD forked KDX to put it on a "diet" and bring it's weight down to something similiar to you hybrid. Curious what your experience with your hybrid would point to for areas to target for weight reduction.

Some of the biggest weight offenders are the simplest stuff, dual-wall pipe and pirate-cannon silencer, kickstand, lighting (and wiring and lighting coil), steel bars, mammoth kick starter, etc. Just pulling the above and replacing with lighter aftermarket items should save a considerable amount of weight. After that theres the little things like steel brake pedal and shifter, the extra frame tubing (that little guy under the silencer, and the tips under the fender), and I believe the swingarm is quiet heavy as well compared to newer designs. Don't forget, even most steel framed motocrossers got an aluminum subframe! And in the end a KDX is wider and bulkier, which adds to the heavy feeling, no matter how light you make it.

By the time you get done trying to make your KDX as light as a 125 you will have it in a 125 rolling frame!

 

[mark_england]

here a picture of the kdx/kx i built for a friend

http://s64.photobucket.com/albums/h165/mark_midlands/?action=view&current=809235457-0.jpg

i used a 99 kx and a 1990 kdx200sr motor.

i stipped the engine down to the bare cases [and had em vapour blasted]
replaced every seal and bearing ,piston etc,,blanked off the oil pump and basically built the engine up as new..
I wanted it to be very reliable, as i was building it for a girl i know and the last thing i wanted was for it to let her down in the middle of no where.

i used a gasgas 200 fmf gnarly pipe [had to dent the back to clear the kips cover]
i stripped the wheels, powder coated the hubs and relaced them with stainless spokes and excel rims [18" rear 21" front]
it was a complete rebuild from the ground up using stainless steel fastners,, it ended up like a new bike

wieghing 106kg fully fueled, [less then a ktm 200exc]
and thats complete with wrapround hand gaurds and enduro bash plate.

i did one cross country race on it [to iron out any bugs]
and loved it so much,,, it made my crf450 feel like a bus.
i decided i wanted one for myself,, im now almost finished a yz/wr hybrid [ 1996 wr200 motor in a 2001 yz125 ]

 

[ukkdxrider]

hi i have a 91 kdx200 and looking to fit a 91kdx250 engine any info would be appreciated i have now got the engine sat in frame fits straight into swing arm ,the engine turns out to be an sr version this has led to some electricle problems due to not having the correct cdi ,however i have fitted kdx125 stator and cdi and flywheel ,the flywheel has to be fitted 180 degrees out (without keyway ) i have to now find a permanent way around this problem either derivet flywheel and refasten or remove the small metle bit that the pick up sensor detects and make a screw on piece ,it is not yet definate that 180 degrees will make the timing correct. the other big problem was the exhaust i managed to find a sr front pipe and got the hax saw out chopped it gutted it reangled it and sawn the end off and welded the 200 end to it ,i have also fitted a 35mm carb and opened up the inlet boot ,i have had it running and sounds very well just have to get the flywheel sorterd and the timing ,oh and ive had to cut the front of frame to allow space for front pipe as it exits the engine higher so i have this to finish 200 sprocket fits straight on and chain ligns up will add more as things progress

 

[arjay]

First off I've got to say what great jobs you guys have done. I've been thinking about this for a long time, and this thread has really got me going.

I have a slightly different proposition and would like to get your thoughts on it.

I've got a fully rebuilt aircooled 87 KDX200 motor ready to go. Rather than put it into the unrestored original boneshaker chassis, I want to find a new home for it. I love the idea of a lowtech woods bike with sharp handling and trick suspension. Having no rads and water could make it a sub 200 lb contender. The engine would be ported for a harder hit.

The natural option (in frame heritage) would be an 86 KX125 with rear disc and linkage suspension. The single down tube fits the side exhaust port. Drawbacks would be that this was a first stab at the format for Kawasaki and only got better from there in. Also it's quite raked out compared to later geometry. 27.5% compared to the contemporary mx'ers, 23 - 25%) The back end could be updated with an 89/90/91 swingarm and linkage.

A guy at the local bike shop has a 94 perimeter chassis. This seems a bit more like it. A bit more work though. It would mean losing the twin cradle and welding in a square section down tube, continuing from where the original one stops. Other issues would be building a pipe for the side port exhaust that goes around the cylinder fins without sticking out too much. I guess the fins could be ground back to accomodate it.

Thanks for any thoughts.

ps has anyone tried running an aircooled 200 motor with modded digital ignition from an 03 onwards KX125? Vortex do a reprogrammable unit for the 125. Maybe mapping could be adapted to suit the 200.

 

[mark_england]

First off I've got to say what great jobs you guys have done. I've been thinking about this for a long time, and this thread has really got me going.

I have a slightly different proposition and would like to get your thoughts on it.

I've got a fully rebuilt aircooled 87 KDX200 motor ready to go. Rather than put it into the unrestored original boneshaker chassis, I want to find a new home for it. I love the idea of a lowtech woods bike with sharp handling and trick suspension. Having no rads and water could make it a sub 200 lb contender. The engine would be ported for a harder hit.

The natural option (in frame heritage) would be an 86 KX125 with rear disc and linkage suspension. The single down tube fits the side exhaust port. Drawbacks would be that this was a first stab at the format for Kawasaki and only got better from there in. Also it's quite raked out compared to later geometry. 27.5% compared to the contemporary mx'ers, 23 - 25%) The back end could be updated with an 89/90/91 swingarm and linkage.

A guy at the local bike shop has a 94 perimeter chassis. This seems a bit more like it. A bit more work though. It would mean losing the twin cradle and welding in a square section down tube, continuing from where the original one stops. Other issues would be building a pipe for the side port exhaust that goes around the cylinder fins without sticking out too much. I guess the fins could be ground back to accomodate it.

Thanks for any thoughts.

ps has anyone tried running an aircooled 200 motor with modded digital ignition from an 03 onwards KX125? Vortex do a reprogrammable unit for the 125. Maybe mapping could be adapted to suit the 200.

cool,,,ive been toying with the idea of building a modern aircooled bike for a couple of years now.
my latest thinking is a aircooled blaster motor [from a quad]
in a newish yz125 frame.

good luck and keep us informed

 

[arjay]

Hi Mark, other aircooled motors that I was thinking about for a 125 chassis were RM250, RM400, PE400, KX250 (all 80/81 vintage - so spares and robustness could be a problem) The RM400 is a great engine, smooth and loads of low end. Just doesn't have primary kickstart. I like the sound of the quad route, newer engines would be better.

Have you got any pics of the WR200?

 

[mark_england]

Hi Mark, other aircooled motors that I was thinking about for a 125 chassis were RM250, RM400, PE400, KX250 (all 80/81 vintage - so spares and robustness could be a problem) The RM400 is a great engine, smooth and loads of low end. Just doesn't have primary kickstart. I like the sound of the quad route, newer engines would be better.

Have you got any pics of the WR200?

yeah its not finished yet but its getting there

 

[arjay]

Mark, that's a beauty. Why didn't Yam build it in the first place?

How tricky was it compared to the KX/KDX?

The DT200 gearbox would go straight into a new Blaster 200 motor, as the cases are the same. The standard cylinders can be ported for 30bhp, and there's a 240 kit that gives 40+. There are heaps of aftermarket tuning parts.

http://www.trengaracing.com/catalog/blaster.php

The cases look kind of dated though, like a DT175. No powervalve, but I guess that keeps things simpler.

 

[mark_england]

Mark, that's a beauty. Why didn't Yam build it in the first place?

How tricky was it compared to the KX/KDX?

The DT200 gearbox would go straight into a new Blaster 200 motor, as the cases are the same. The standard cylinders can be ported for 30bhp, and there's a 240 kit that gives 40+. There are heaps of aftermarket tuning parts.

http://www.trengaracing.com/catalog/blaster.php

The cases look kind of dated though, like a DT175. No powervalve, but I guess that keeps things simpler.

i'd say its a simpler conversion then the kdx/kx, but the basics are the same

new frame brackets
machine a carb/airboot spacer
space the swingarm to fit the engine
find a suitable exhuast (on the kdx/kx i used a gasgas200 exhaust, on the wr/yz i used a wr200 fmf pipe and just made a new angled manifold and cut a bit off the tail end)

probably about the same amount of work , but the wr/yz just seemed to go together easier

 

[DirtDawger]

I just want to say what a great thread this is. I no longer have a KDX but have always wanted to do this mod. Maybe it's time to break out the welder. :yikes:

 

[KDX200Kev]

Heres a pic of the KDX/KX Hybrid that my friend purchased and I modified for him.

 

[arjay]

I had an 89 kx125 with an air cooled kdx200 motor about 4 years ago. Wish I had never sold it. I' v just come across a complete rolling kx125 frame and was thinking I could make another one. I never really took much notice of my old one but was wondering how easy the motor slotted in and were there any major mods to do to get it to fit. The old one just looked like it was made like that from the factory. Do any of you guys know?

Hey Rog, could you email me. I'd like to get some advice from you on the down tube set-up.

Thanks

- Nice job Kev. What forks are those?

 

[GS]

What year(s) of KX chassis would be prefered for the conversion??
Have a 03 KX125...love the handling and a '99 KDX220 of which I love the power delivery. Won't use these two, but what generation of KX makes sense?? I can "ebubbl bait an engine :coocoo: , me-guesses :ride:
Greg