Stock KDX200/220 Shim Stack Mod

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KDXohio
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Stock KDX200/220 Shim Stack Mod

Post by KDXohio »

Stock KDX 200/220 Free Fork Shim Stack Mod

Tools Needed:
14mm hex w/ 1/2 driveor proper adapter
1/2 drive impact gun
12mm or 10mm wrench

1. Raise and support the front end of the bike
2. Remove the Front caliper
3. Remove the front wheel
4. Un-clamp the brake line from the left fork and position aside
5. Loosen the triple clamp for one fork then remove that fork
6. Repeat step 5 for remaining fork
7. There is no need to drain the fork oil unless you want to change it
8. Pick a fork to be specimen number 1
9. Turn it upside down and compress it
10. Remove the rubber plug that protects the compression clicker
11. Using your impact driver and 14mm hex, loosen the valve assembly from the bottom of the fork ****Note that you should release the compression of the fork once the valve is loose enough to remove by hand****
12. On top of the valve assembly there is a nut you will need to remove it. ***Note that the thread on the shaft is staked at the top, so the nut will be hard to remove. Once it is off, clean up the top of shaft thread with a file, to make it easier to remove the rest of the components****
13. Under the nut is a plate and spring. The plate has 'fingers' that curve down and hold a series of thin washers, these are the SHIMS. ***note direction for reassembly***
14. There will be 10 shims - take two of them out. Put the rest back onto the stack (inside the 'fingers') and place the whole assembly back onto the shaft. ***Note don’t assume there’s 10 there somebody may have done this mod already so count them***
15. Apply some locktite (or equivalent thread locker) to the threads this is important as you have filed off the locking tabs
16. Replace the nut and tighten it up 25 in/lbs (Too tight and you will strip the thread turning a free mod into a stupid repair).
17. Make sure the valve is clean free of any metal filings from step 12 before placing it back into the bottom of the fork. Compress the fork once more and start the valve by hand 2-3 turns before using the impact driver to tighten the valve in the bottom of the fork
18. Set the fork aside and grab number 2 and repeat steps 9-17
19. Once completed do steps 1-6 backwards and obviously change loosen to tighten, raise to lower, un-clamp to clamp and remove to install I shouldn't have to say that.

This mod really is free and noticeably improves the action of the fork on hard, square edged bumps such as rocks and roots. This is because the shims absorb the initial impact (the high speed circuit) by restricting oil flow before the fork springs start to take the shock (the slow speed circuit). The rocks and roots don't make the forks move deeply enough for the springs to take up enough of the impact. By removing two shims you are reducing the resistance to the oil flow and therefore making that initial stroke plusher - just enough to make the front end a lot less jittery over the sharp stuff. If you think it is a little too soft now, simply replace one shim. Gold valves have a more advanced shim stack and can be tuned a lot more precisely than the stock valve. They also cost $$$ whereas this mod is totally free unless you value your’ labor.
Last edited by KDXohio on 12:02 am Jul 29 2013, edited 2 times in total.
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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Re: Stock KDX200/220 Shim Stack Mod

Post by Postigo »

New springs for your weight and shim stack mod make a huge improvement to kdx front suspension. Those instructions are very straight forward the on thing I notice is the part of installing back the valve with an impact tool. I do not recommend the use of an impact tool to install the valve because the valve body is aluminum and you can strip the treads of the valve pretty easy, is better to hand tight the valve with the hex wrench.
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Re: Stock KDX200/220 Shim Stack Mod

Post by KDXohio »

Postigo wrote:New springs for your weight and shim stack mod make a huge improvement to kdx front suspension. Those instructions are very straight forward the on thing I notice is the part of installing back the valve with an impact tool. I do not recommend the use of an impact tool to install the valve because the valve body is aluminum and you can strip the treads of the valve pretty easy, is better to hand tight the valve with the hex wrench.
The issue is being able to fully tighten it by hand without a cartridge holding tool yes that is always better but the majority of people don't have it so you just have to know your tool and know to stop when the valve stops turning. I did change it to say to start it by hand I didn't realize I had left that out
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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Re: Stock KDX200/220 Shim Stack Mod

Post by KDXGarage »

I would suggest flat filing the peening / staking off before removing the nut. Also, 25 inch-pounds on the nut.

Low speed compression damping adjustment is the bypass valve inside the compression adjuster / base valve. Also, don't forget the cartridge rod moving through the cartridge.
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Re: Stock KDX200/220 Shim Stack Mod

Post by Postigo »

KDXohio wrote:
Postigo wrote:New springs for your weight and shim stack mod make a huge improvement to kdx front suspension. Those instructions are very straight forward the on thing I notice is the part of installing back the valve with an impact tool. I do not recommend the use of an impact tool to install the valve because the valve body is aluminum and you can strip the treads of the valve pretty easy, is better to hand tight the valve with the hex wrench.
The issue is being able to fully tighten it by hand without a cartridge holding tool yes that is always better but the majority of people don't have it so you just have to know your tool and know to stop when the valve stops turning. I did change it to say to start it by hand I didn't realize I had left that out
Either way you need a special tool or a ratchet tie down to compress the cartridge before removing the valve and it can be used to compress the cartridge during the valve installation.
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Re: Stock KDX200/220 Shim Stack Mod

Post by MCKDX220 »

Just wanted to add my .02 cents worth. I have a new to me 00 KDX220 and on my maiden voyage the bike pitched me off and I did a pretty nasty rag doll, which injured my shoulder. The rebound was way to quick and the compression was terrible. I ventured into putting on a KX front end and decided that I wanted to try to make the existing forks work better before going that direction.

I decided to try removing the 2 base valve shims and try that route first, however when I got into the base valves, the previous owner had already removed 2, so I decided to remove 2 more and go with the thicker mobil 1 synthetic ATF, to slow down the rebound.

Well, I took it last weekend to try to dial in the balance, as I also put on a KLX 300 set of Pro Circuit dog bones I had laying around the tool box, to try to drop the rear end a bit. At first I could not get a feel for the suspension, because the balance was noticeably off, so I proceeded to go back to truck and make the appropriate fork height adjustment. I nailed the balance on my first attempt. OK, back to the trails, well I can say is the best fork action I have ever felt, no, but is the best stock fork action I have ever felt.

Any rate, I think I can smooth things out just a bit better, if I remove some fork oil as I have my setting @ 100mm fork oil height. When my schedule permits, I am going to try 110mm fork oil height. Just a side note, the PO had also installed a pair of aftermarket .41kg fork springs, so I am not dealing with stock fork springs. I also decided to add a FRP handle bar brace, which should keep the forks straight in case of a get off, (hey it happens).

All in all, I am reasonably happy and see no need to get a set of USD forks off a KX. While I was riding standing up I can say this bike is quite the neutral turner (good thing), it definitely rewards while standing, sitting down, I did not feel as comfortable. I think it just hides its weight a whole lot better standing, for a 2 stroke it is pretty heavy.

Michael
87 KDX200 / 02 KTM 520 EX/C / 87 XR 200 / 90 XR 200
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Re: Stock KDX200/220 Shim Stack Mod

Post by Postigo »

I have the same mod in my 220 and is a night and day difference and as you said for now I don't feel the need of USD forks.
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Re: Stock KDX200/220 Shim Stack Mod

Post by crs »

I realise this could be a dumb Q but what about this mod on 89-92 forks? Same deal or not?
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Re: Stock KDX200/220 Shim Stack Mod

Post by KDXGarage »

Not applicable to 1989 - 1992 KDX200.
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Re: Stock KDX200/220 Shim Stack Mod

Post by crs »

Yeh - thanks. The Race Tech Emulators are all I can try, I guess. (Fredette's said welding and drilling the damping rod can work OK but that means, once it's done, you can't change things for different weights or conditions...)
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Re: Stock KDX200/220 Shim Stack Mod

Post by 6 Riders »

I had my 94 forks drilled....I forgot about that....these forks suck so bad (in stock form) why would you ever want to go back?
newbbewb wrote:^what he said.
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Re: Stock KDX200/220 Shim Stack Mod

Post by crs »

Just thinking about lighter / heavier riders if I sell, really...
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Re: Stock KDX200/220 Shim Stack Mod

Post by 6 Riders »

Drilling the dampening rod has nothing to do with weight, thats mostly springs and oil, it just lets the oil flow a little easier.
You can always talk to the guy that did my forks....$250 OTD w/springs and drilling, they are like butter now.
His suggestion, over going with Gold Valves, was a fork swap with 1" of lowering (KX forks are longer than KDX forks) and a valve job.
here's his site.....http://www.ltracing.com
He is super busy just before April, supports all levels of riders.....just saw him at a vintage MX that my club puts on. Great gut, lots of knowledge and probably point you in the right direction.
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Re: Stock KDX200/220 Shim Stack Mod

Post by crs »

Thanks for the info. Problem is I'm in Thailand... Great trails but terrible for sourcing bike's, parts - and suspension specialists. And postage from the US for a set of KX forks, clamps, wheel won't be cheap! Talking to Jeff Fredette now about him just sending over some done rods... Cheers.
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Re: Stock KDX200/220 Shim Stack Mod

Post by twowheelfanatic »

im new to this site and have a new to me 2000 kdx 200.im thinking of doing this shim mod.when removing the shims which ones do you take out ?or are all of the shims the same?also what do you do if the valve wont come out due to cartridge spinning?
thanks
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Re: Stock KDX200/220 Shim Stack Mod

Post by KDXGarage »

Welcome to the forums.

Buy or make the cartridge holding tool to keep the cartridge from spinning.

All the shims in the 1995+ forks are the same size.
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Re: Stock KDX200/220 Shim Stack Mod

Post by twowheelfanatic »

thanks for the info.i cant wait to see how much this mod changes how the forks work over tree roots.i will post my results.
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Re: Stock KDX200/220 Shim Stack Mod

Post by KDXGarage »

Don't forget having the correct spring rates and preload amount front and rear to get it all working well.
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Re: Stock KDX200/220 Shim Stack Mod

Post by twowheelfanatic »

ive got the proper springs for my weight and planning on installing them with this fork mod.what is recomended for front fork free sag?
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Re: Stock KDX200/220 Shim Stack Mod

Post by KDXGarage »

the same amount as in your other post asking the same thing??
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