fork seals and spring replacement

Discussion specific to the 1995 - 2006 KDX200 (H Series) and 1995 - 2005 KDX220R (A Series) models sold in the USA
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KDXrider007
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fork seals and spring replacement

Post by KDXrider007 »

I just decided to jump in today and start on this. I got the forks off, one fork is tore down pretty good. I drained the oil out the best I could from the top got the spring off the rod. Now I'm kind of confused do I just pop the new spring in or do I have to change the metal tubing that is in between the spring and the cap? I assume this tubing is how you get preload on the spring am I correct? I went with racetech springs .46kg. i honestly don't know what i'm doing i just watched a couple youtube videos lol.

basically do I have to use these washer looking things and the metal tubing that race tech sent me? or can I just use what was already in there and just swap springs? Another question is I guess how do I add oil since I dumped all the oil out of the top and how much do I add?

here's pictures of everything so far. the long tubing is what racetech sent me the tubing with the measuring tape on it is what was in the bike.

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bufftester
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Re: fork seals and spring replacement

Post by bufftester »

Are you also doing seals and wipers? This is the point where we point out that the cost of a service manual is well worth it. Once you have the fork reassembled (if doing seals) you leave the spring out, and fully compress the fork . Add oil and pump the rod to remove air bubbles. You measure the oil level from the top of the fork leg with the spring removed and the leg compressed, it should be 85-89 mm from the top. Once oil is added, extend the fork and install the fork spring, fork spring seat, spacer and washer into the fork tube. I would use the same spacer (the short metal tube) that came out to start with. My Racetech springs did not come with a long tube like you have in your pics, so not sure what that is for. Verbatim from the manual: "Clean the fork cap bolt with aerosol brake cleaner, apply blue Loctite and torque the fork cap bolt against the nut to specification. (Specification for fork cap bolt to nut torque is 15 N-m or 11 ft-lb). Thread the fork cap bolt into the fork tube and torque it to specification. (Specification for fork cap bolt torque is 29 N-m or 22 ft-lb)"

Service Manual and a torque wrench, two items you absolutely should spend money on regardless of which bike you own.
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Re: fork seals and spring replacement

Post by KDXGarage »

I will differ a little. Do use the tube they included or a length of 1" PVC pipe to make spacers that will give around 4 mm of preload. You are correct in the tube being for preload.
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KDXrider007
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Re: fork seals and spring replacement

Post by KDXrider007 »

bufftester wrote:Are you also doing seals and wipers? This is the point where we point out that the cost of a service manual is well worth it. Once you have the fork reassembled (if doing seals) you leave the spring out, and fully compress the fork . Add oil and pump the rod to remove air bubbles. You measure the oil level from the top of the fork leg with the spring removed and the leg compressed, it should be 85-89 mm from the top. Once oil is added, extend the fork and install the fork spring, fork spring seat, spacer and washer into the fork tube. I would use the same spacer (the short metal tube) that came out to start with. My Racetech springs did not come with a long tube like you have in your pics, so not sure what that is for. Verbatim from the manual: "Clean the fork cap bolt with aerosol brake cleaner, apply blue Loctite and torque the fork cap bolt against the nut to specification. (Specification for fork cap bolt to nut torque is 15 N-m or 11 ft-lb). Thread the fork cap bolt into the fork tube and torque it to specification. (Specification for fork cap bolt torque is 29 N-m or 22 ft-lb)"

Service Manual and a torque wrench, two items you absolutely should spend money on regardless of which bike you own.

I agree I don't own a torque wrench I'm going to need one soon so I'll probably pick one up. I am going to replace the seals as it was leaking. As far as wipers I have no clue what a wiper is lol :toimonster:
KDXrider007
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Re: fork seals and spring replacement

Post by KDXrider007 »

Jason wrote:I will differ a little. Do use the tube they included or a length of 1" PVC pipe to make spacers that will give around 4 mm of preload. You are correct in the tube being for preload.
forgive my ignorance but how do I know how long I need to get 4mm of Preload. I measured the spacer in there originally. Should I add a couple mm to the spacers already in there? I will have a hard time cutting them square which is my only fear regarding using the spacer tubing they sent me.


EDIT: is this a wiper? I found this in the fork boot lol

Last edited by KDXrider007 on 09:35 pm Feb 22 2017, edited 1 time in total.
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Re: fork seals and spring replacement

Post by KDXGarage »

Yes, that is a seal.

Can you search for preload? I think I just posted how to do it maybe two weeks ago??

The goal is to compress the spring 4 mm when it is all fastened together.
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Re: fork seals and spring replacement

Post by bufftester »

what he said....http://www.kdxrider.net/forums/viewtopi ... ad#p183981

super easy way to picture it and figure it out. I would also recommend using 1" pvc, it's cheaper and easier to cut. If you arent perfectly square it doesn't really matter
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Re: fork seals and spring replacement

Post by KDXGarage »

Get a flat surface, some sandpaper and do figure eights with the pipe ends, then debur.

Also, I need to clarify, yes, that is a dust seal. It may also be seen as referred to as a "wiper".

Be aware of the circlip.
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Re: fork seals and spring replacement

Post by KDXrider007 »

alright that sounds pretty straight forward. I bought 2 quarts of AMSOIL shock therapy light #5 suspension fluid, should be enough right? I do have a question what would happen if I were to use the stock preload with the stiffer springs as opposed to finding the right preload would it be noticeable if I don't race or jump it? Would i still notice the stiffer springs?

also do I need fork seal oil (EDIT grease) as that is one thing I forgot to buy?


thanks for all the help
Last edited by KDXrider007 on 11:33 pm Mar 01 2017, edited 1 time in total.
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Re: fork seals and spring replacement

Post by KDXGarage »

Just run whatever preload. You are determined to do it that way.

Did you buy suspension oil or shock oil?

I have never heard of fork seal oil, but have heard of fork oil.
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Re: fork seals and spring replacement

Post by KDXrider007 »

Jason wrote:Just run whatever preload. You are determined to do it that way.

Did you buy suspension oil or shock oil?

I have never heard of fork seal oil, but have heard of fork oil.
fork seal grease? I'm not sure just saw it in a video didn't know if it was vital as I only have regular marine grease.

"AMSOIL Shock Therapy light #5 suspension fluid for shocks and forks" -- that's what the bottle says it's all they had at napas aside from ATF.

As far as preload, I was just asking... I'm not confident I can do it right. The problem I was having was the front end would almost dive down when you just touched the front of the bike (aside a leaky seal).
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Re: fork seals and spring replacement

Post by KDXGarage »

Have you got something lighter? Just use the oil as a mounting lube.

That oil will be fine.

Preload is not too hard to figure out. If it has stock springs, it will dive pretty easily.
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