Finding Fork Bushings for '81

Discussion specific to the various air-cooled KDX models sold in the USA
Devon007
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Re: Finding Fork Bushings for '81

Post by Devon007 »

Goofaroo wrote: 09:25 am Feb 10 2021
Devon007 wrote: 12:02 pm Feb 09 2021
Goofaroo wrote: 07:41 am Feb 09 2021

It would be interesting to see if a factory manual gave any service limit dimensions or further information.
I have the factory manual. It has info on oil but not the "bushings".
If you have a few tools and the inclination to fix these forks yourself you could just go to the shop and bring them home. These early forks are very simple to work on. If you continue to post here or start a build thread you’ll certainly get plenty of help if you need it.

Is this bike running and ridden routinely? Are you just trying to fix an oil seal leak in the forks?
Next time I'll do it myself (with everyone's kindly assistance here). The bike was running great until it needed top end service and I've taken this opportunity to take care of the front suspension which bottomed out on me a couple times even though I wasn't riding that hard or heavy. Also I am messing with the front brakes to try to get better stopping power, and replacing front wheel which had spidery cracks with a relatively new one.
Devon007
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Re: Finding Fork Bushings for '81

Post by Devon007 »

KDXGarage wrote: 10:08 pm Feb 09 2021 If they are still decent, ride it.

This thread has been VERY educational to me, and I thank you!

A KDX front end from a newer model should not be too terribly expensive, but shipping would be a bear. A newer KDX might have slighter longer travel (taller forks), but hopefully not so bad that one could not just raise the forks a touch in the clamps to compensate.

What state are you in?
In Fresno, California.
Goofaroo
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Re: Finding Fork Bushings for '81

Post by Goofaroo »

While the forks are being serviced you could make them a bit more resistant to bottoming with very little effort.

First you can use heavier oil in the forks and use the higher level or quantity listed in your service manual. If you don’t know what weight the oil was you could try 10wt and go from there.

Also you could make a longer spacer from pvc pipe to add more preload to the spring. This will help get your bike back to factory ride height and can help tremendously although it is no substitute for stiffer springs if you’re a fast rider and a “heavy” guy.

If your forks have not been serviced for a very long time and/or the seals were leaking the suggestions above will help considerably with hardly any additional investment.
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Re: Finding Fork Bushings for '81

Post by KDXGarage »

Well, dang. No drive over to go through the hoard and find you something. LOL

If the wheel is shot, do consider a front end swap at some point in the future. A 1986 (or newer) KDX front end has a disc brake instead of drum.
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
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Re: Finding Fork Bushings for '81

Post by Goofaroo »

[/quote]
Next time I'll do it myself (with everyone's kindly assistance here). The bike was running great until it needed top end service and I've taken this opportunity to take care of the front suspension which bottomed out on me a couple times even though I wasn't riding that hard or heavy. Also I am messing with the front brakes to try to get better stopping power, and replacing front wheel which had spidery cracks with a relatively new one.
[/quote]

When you said the “front wheel has spidery cracks” are you talking about the actual wheel or just the tire? Do you have any pics of this bike?
Devon007
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Re: Finding Fork Bushings for '81

Post by Devon007 »

Goofaroo wrote: 09:07 am Feb 11 2021
Next time I'll do it myself (with everyone's kindly assistance here). The bike was running great until it needed top end service and I've taken this opportunity to take care of the front suspension which bottomed out on me a couple times even though I wasn't riding that hard or heavy. Also I am messing with the front brakes to try to get better stopping power, and replacing front wheel which had spidery cracks with a relatively new one.
[/quote]

When you said the “front wheel has spidery cracks” are you talking about the actual wheel or just the tire? Do you have any pics of this bike?
[/quote]

The front wheel has the spidery cracks, not the tire. The local tire shop said they thought it was okay to ride but didn't want to put it in their machine to change the tire. Yes, yes, I know I could do it myself still with levers but the tire shop is quick, close, and cheap.
Devon007
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Re: Finding Fork Bushings for '81

Post by Devon007 »

KDXGarage wrote: 08:44 pm Feb 10 2021 Well, dang. No drive over to go through the hoard and find you something. LOL

If the wheel is shot, do consider a front end swap at some point in the future. A 1986 (or newer) KDX front end has a disc brake instead of drum.
:boogie: disc brakes would be so nice! :boogie:

Definitely will keep an eye out for a 1986+ front end. Looks like many sellers on ebay for less than $100 including shipping.
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Re: Finding Fork Bushings for '81

Post by Goofaroo »

Trying to switch forks might open a new can of worms. Maybe someone can chime in and tell you if it is a direct bolt on or will require machining or other modifications. Not to mention the geometry. The 86-88 forks probably have more travel and possibly more offset.

Whatever you do keep the original parts in case you decide to sell the bike. Someone may want to do a full restoration on it. The early models are getting hard to find.
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Re: Finding Fork Bushings for '81

Post by Devon007 »

Goofaroo wrote: 03:16 pm Feb 11 2021 Trying to switch forks might open a new can of worms. Maybe someone can chime in and tell you if it is a direct bolt on or will require machining or other modifications. Not to mention the geometry. The 86-88 forks probably have more travel and possibly more offset.

Whatever you do keep the original parts in case you decide to sell the bike. Someone may want to do a full restoration on it. The early models are getting hard to find.
Will definitely look before I leap on the fork exchange. Won't be this year, anyway. And will keep the original forks.
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Re: Finding Fork Bushings for '81

Post by Devon007 »

UPDATE
Picked up forks from suspension shop. The mechanic reported: there are no bushings to be removed/replaced. There are bushings, he said, but they are pressed into the lowers as-manufactured and not removable or replaceable.

I am looking forward to getting the front put back together this weekend.
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Re: Finding Fork Bushings for '81

Post by Goofaroo »

I’m glad they were still serviceable. That’s a nice step forward.
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Re: Finding Fork Bushings for '81

Post by KDXGarage »

THANK YOU for the follow-up. I appreciate it.
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
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