My 87 KDX200 project.

Discussion specific to the various air-cooled KDX models sold in the USA
bob_jones
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Re: My 87 KDX200 project.

Post by bob_jones »

kawagumby wrote:Hi,
No unusual problems fitting the YZ forks (or WR for that matter - WR250 forks wouldn't likely need a revalve). You would need to use an E or H model stem (they are the same) pressed into the yz/wr triples.

So are you saying you put a WR front end in a c series kdx?

The reason I ask is because all balls doesn't show a conversion kit so I figured it would fit.
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kawagumby
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Re: My 87 KDX200 project.

Post by kawagumby »

No conversion kit necessary...the original C model type steering head bearings are used....because the KDX E or H stems are the same (bearing-wise) as the C model. The Kawasaki stem is pressed into the YZ or WR lower triple (the same method as if you used a KX front end) which may or may not require the kawasaki stem to be knurled (same as the KX conversions) to make a press fit. I had one H model stem that didn't need to be knurled and one that did, for different YZ triples from the same year-model bike, no less. Weird.
The nice thing about using the 2001 on up Yamaha triples is that the height is perfect for the top stem nut thread length-wise, i.e. no spacer is needed. Use aluminum pie-pan as shim stock to wrap around the stem at the upper triple....that's no big deal. Using the 2001 on up yamaha triples also moves the the handlebar position further forward which really helps the handling, IMO.

BTW, this bike uses YZ forks, not WR forks...the difference is in the valving and stock spring rate. I had originally used WR fork compression shim stacks which didn't work out, and finally went to my own shim configuration using YZ shim stacks.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
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Chuck78
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Re: My 87 KDX200 project.

Post by Chuck78 »

This bike is exactly what I wish I had! I was telling my brother if I found a KDX 200 C for a good price, I might sell him my KDX 220 minus my new 01 KX500 forks... I love the old air-cooled monsters. I'm thinking a good pipe and piston would increase the power output on the 86-88 KIPS engine enough. I wonder if there is any head work that could be done to yield similar gains as the RB squish mod on the 220's?

Your write up on the rear brake retrofit was also inspiring material for me. Now I just need to get this 1974 Rickman 250 put back together as a decent old school trail machibe with 1" more suspension front and rear, and tackle this 1977 PE 250 Suzuki resto-mod!!! Longer travel front and rear, fox factory shox & RaceTech DR250 forks... ported cylinder, wiseco piston....

Look me up if you ever part ways with this sweet C model
'97 KDX220R - purple/green! - KLX forks, Lectron, FMF, Tubliss
'99 KDX220R project - '98/'01 RM125 suspension, Titanium hardware, Lectron Billetron Pro, Tubliss
'77 Suzuki PE250 & '83 Suzuki PE175 Full Floater - restomod projects
'77 Suzuki GS750-844cc, '77 GS400/489cc & '77 GS550/740cc projects
'62 GMC 1000 Panel Truck
'88 Suzuki Samurai TDI/Toyota swaps
'88 Toyota 4x4 pickup
Myersprostatus
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Re: My 87 KDX200 project.

Post by Myersprostatus »

What size YZF FORKS DID YOU SWAP IN THERE? Yzf250? Love your set up man. Very similar to what I want to do. I was thinking about swapping in some kx500 forks due to the comparability, but after reading what you said about the geometry of the front end and placement of the handle bars moving forward I am tempted to go the YZ route. Do you think the kx500 fork swap would have a similar effect on the kdx?
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kawagumby
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Re: My 87 KDX200 project.

Post by kawagumby »

The forks were 04 YZ250F units, 48mm. I did a kx500 fork swap on an H model, and I recall that the triples I used (can't remember the year bike they were from) did not move the bars as far forward as I would like...I remember fighting the front end turn-pushing in some situations, which did not occur with bikes using the 01-03 era yamaha forks/triples I'd used for other bikes. I would not recommend using the larger 48mm diameter forks like I did...they were only made the one year (04 as larger diameter with open chamber design and stock 43 kg rate springs) - so that means you would have to do more work finding parts to repair and modify the setup. What I recommend and used on three other KDX conversions is the 01-03 yz 125 forks. They have a stock spring rate that is closer to what most guys would want (41's). The modified for-off-road compression valve stack spec's I show somewhere in this thread is based on the 125 fork setup.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
Myersprostatus
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Re: My 87 KDX200 project.

Post by Myersprostatus »

Thanks for the info man. I really appreciate it. What size are the 01-03 125 forks if they are not 48mm? Did you have to run a shin in those as well? Or is it a pretty straight forward swap? Again, thank you for the info. I’m gonna bring this bike back to life and then some. Haven’t been excited about a project in some time. Cheers!
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kawagumby
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Re: My 87 KDX200 project.

Post by kawagumby »

The 125 forks are 46mm. They do take some shimming around the steering head stem, but not on the top of the triples. They're a pretty good setup all around. Have fun with your project!
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
Pressingonward1
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Re: My 87 KDX200 project.

Post by Pressingonward1 »

Very nice build, thanks for sharing. Gives me some very useful info for my 88.
arjay200
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Re: My 87 KDX200 project.

Post by arjay200 »

Inspiring build, very nice. Could I pick your brains on the H flywheel conversion - and the FRP modded stator pic you posted a few years back?
I have an 87 which I'm converting to H coil, flywheel and CDI. I've re-slotted the 87 stator at exactly 90 degrees to the standard holes. Looking at other pics (like the FRP one) the holes are not 90 degrees, more like 75 deg offset. I've included a pic of mine, and a pic from a forum member who I can't get hold of. Do you think I need to start cutting new slots? Thanks for any advice.

Also (I'm not sure if you did this mod) but do you need the generator cover off the H?
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kawagumby
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Re: My 87 KDX200 project.

Post by kawagumby »

Hi,
Forum member Hail Seizure did the mod, and reported that it worked with a 90 degree rotation. I never did the mod as I had good original flywheels.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
arjay200
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Re: My 87 KDX200 project.

Post by arjay200 »

kawagumby wrote: 01:51 pm Jan 06 2020 Hi,
Forum member Hail Seizure did the mod, and reported that it worked with a 90 degree rotation. I never did the mod as I had good original flywheels.
Cool, thank you
Pressingonward
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Re: My 87 KDX200 project.

Post by Pressingonward »

Google keeps bringing me back to your sweet bike while researching for my 1988 - nice work on it!

Question for you - I see you used a Yamaha master cylinder for the rear disk conversion, but what brake pedal did you use? From what I can find, most people use a KDX200 E or H pedal, but I'd like to run an aluminum pedal for the admittedly minor weight savings, and it looks like yours is aluminum?

I bought a 1986 KX125 rear pedal off ebay, but it's hitting the peg mount on the front side, so it's not going to work. Your brake pedal looks similar, but it's got plenty of clearance from what I can see
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kawagumby
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Re: My 87 KDX200 project.

Post by kawagumby »

Hi,
The pedal I used was an H model KDX slightly reshaped, not aluminum.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
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Re: My 87 KDX200 project.

Post by Pressingonward »

Thanks for getting back to me. I bought an aluminum YZ pedal that looks promising, but if that doesn't work out I'll pick up an H series KDX pedal
bob_jones
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Re: My 87 KDX200 project.

Post by bob_jones »

I also used the steel h series pedal on conversion and I had to bend it, which would have been a struggle with aluminum
TheGarBrah
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Re: My 87 KDX200 project.

Post by TheGarBrah »

Kawagumby, what kind of rear fender do you have on your KDX ? I'm looking for an MX style fender like yours
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kawagumby
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Re: My 87 KDX200 project.

Post by kawagumby »

The fender is an 86 kx125/250/500 rear: Maier Mfg 145023 rear fndr kx125/250/50 grn Green M14502 65-4502 MM145023
Some trimming, but I installed a curved flat aluminum mounting brace (1/4 x 1" you get at the hardware store), threaded in the middle to attach fender and bolted to the existing frame end point holes. If you look at the pictures you can see the screw head. It works pretty well.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
TheGarBrah
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Re: My 87 KDX200 project.

Post by TheGarBrah »

kawagumby wrote: 12:34 pm Feb 01 2021 The fender is an 86 kx125/250/500 rear: Maier Mfg 145023 rear fndr kx125/250/50 grn Green M14502 65-4502 MM145023
Some trimming, but I installed a curved flat aluminum mounting brace (1/4 x 1" you get at the hardware store), threaded in the middle to attach fender and bolted to the existing frame end point holes. If you look at the pictures you can see the screw head. It works pretty well.
Awesmome thanks for the info. I bought the same rear fender I just wasn't sure how you were mounting it.
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KDXGarage
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Re: My 87 KDX200 project.

Post by KDXGarage »

UFO used to make one also. It is for 1986 - 1987 KX125 / KX250 / KX500

Look on denniskirk.com
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
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