Upgrade front end on 83 KDX 200

[Zet]

1983 KDX 200 A1
I want any opinions on the best way ( Cheapest ) to convert
my shoe brake front end to a disk one.
I.E. replace forks & tripples clamps to at least 43 mm, etc
please reply if you have knowledge of a succesful conversion
or have any ideas. :clue:

Thanks Aussie ZET

 

[JasonWho]

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[Matt90GT]

if you can find a 86-89 front end, it is a direct swap. You need to get it complete with wheel assembly or at least the hub. Then install some XR400 fork springs in place of the stockers to stiffen it up.

 

[MadArrow]

Will the XR400 springs fit in an 85 front end or does it have to be the 86-88?

 

[Zet]

Mad Arrow
I'm not 100% sure but the 83-85 models have 38mm forks, therefore the 400 springs (to suit a 43mm fork) may be too large a diameter to fit.

Thanks to the other posters

My mate "Holeshot" has done a 86 conversion to his 85 as per Matt90GT
It works well but the brakes do not feel modern ( smooth & Linear )
I was wondering if anyone has fitted a 98 or newer front wheel to an 83-86 and welded caliper mounts to the fork leg.
If so how did it feel.
Or is it not feesable???

Zet

 

[Matt90GT]

Mad Arrow
I'm not 100% sure but the 83-85 models have 38mm forks, therefore the 400 springs (to suit a 43mm fork) may be too large a diameter to fit.

Thanks to the other posters

My mate "Holeshot" has done a 86 conversion to his 85 as per Matt90GT
It works well but the brakes do not feel modern ( smooth & Linear )
I was wondering if anyone has fitted a 98 or newer front wheel to an 83-86 and welded caliper mounts to the fork leg.
If so how did it feel.
Or is it not feesable???

Zet

we did not get the MC with the front end. So we used an early 90s Honda CR master cylinder. It brakes great! I would suggest to try a CR master cylinder (I assume they use a larger bore than the KX/KDX models, thus the improved feel). They are cheap on ****.

WTF? E B A Y is now an edited word? HOLY SHEOT!, stupid

 

[JasonWho]

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[Jon K.]

The '86 KDX front end is light-years ahead of the '83.

Go for it! :aj:

 

[dirt bike dave]

Yep, and put some Race Tech cartridge fork emulators in the '86 forks.

I loved my '84 KDX200, but the forks and the front brake were not good. As a temporary fix to help your stock forks, you can cut a few coils off to stiffen the springs and raise the oil level to improve bottoming resistance. Not much you can do about the stock front brake though. It was weak even by early '80's standards.

 

[JasonWho]

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[dirt bike dave]

Jason - I meant the stock front brake on the '84 front end was weak.

Also, '89 was the first water cooled KDX and was virtually all new compared to the '86 - '88 (first disc brake and KIPS).

 

[Zet]

Dirt Bike Dave
These cartridge fork emulators sound good. How much US$ and how much improvement
plus is there any loss of feel. Should I fit XR400 fork springs also?

Air cooled rules! plus you've gotta love that 2 stroke coastability after rolling off the throttle. We may sorely miss the strokers.

Thanks all, Zet

 

[dirt bike dave]

Zet - RT's cartridge fork emulators retail for $150 US, but I've seen them for $135.

They should be used with stiffer than stock springs; I think your stock '85 springs are like 0.33 kg/mm; maybe even 0.31 kg/mm, too soft! The XR400 springs in an '86-'88 fork might be a little stiff, but that depends on your weight and personal preferences. Remember, your '85 is lighter than water cooled KDX's and much lighter than an XR4.

With the KDX, Kawasaki has a long tradition of very soft springs with too stiff high speed compression damping to compensate for the wimpy coils. This might be OK on a street bike, but is bad in the dirt, because your fork is too harsh on rocks and roots which cause high speed movement of the fork, but the soft springs cannot control big hits like whoops and jumps.

With the cartridge fork emulators, you drill huge new holes in the damping rods, allowing lots of oil to flow. (If you are handy, it is a do-it-yourself job). The emulator sits on top of the damping rod, and the oil must flow through orifices in the emulator and move a spring loaded plate. The high volume of oil flow allows the fork to respond much quicker on 'sharp' hits, and the stiffer fork springs will really help on jumps and whoops. Made a huge improvement on my '90 KDX. Ride was still plush at slow speeds, even with stiffer springs (I think I had 0.38 kg/mm).

BTW, be careful about coasting any hot two stroke at high rpm. If your hot motor is spinning fast and you deprive it of cooling fuel and lubricating oil, things can go boom. Rolling off the throttle going into corners is no problem, but backing off and coasting at 60+ mph after 2+ miles of top gear WFO should be avoided. I learned the hard way on that (very expensive lesson).

I loved my old '84 - glad to see you are enjoying your early KDX.

 

[JasonWho]

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[Zet]

DBD & Jason, Thanks for the advice on the coasting & the emulators, looks like I'm off to find some forks etc.

Thanks to all, Zet

 

[Matt90GT]

Matt90GT: Is there something different about '90 - '92 that makes tham NOT a direct swap compared to '86 - '89?

the easiest way to check is to get into the Buykawasaki.com microfiche and check the head stem bearing part numbers. if they are the same, it is a simple swap.

if they are not, you need to find out the dimensions of both the stock and "new" fork steam bearings. Then take the OD of the stock and the ID of the new ones and try to find a match in a bearing book like Timken or BCA.

 

[JasonWho]

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[Matt90GT]

Wait. Did you get rid of your KDX250?? I was on here very little during the winter. What happened?? I don't see it in your list of bikes.

Yup, the KDX is gone. YZ426 now.

The KX and KDX bikes when they get into the inverted forks use different top bearings. Means you may have to press yoru stock steering stem into the KX clamps (as long as the bottom bearing is the same) to make it work.

 

[JasonWho]

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