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2004 kx250 forks don't rebound all the way

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When riding my kx250 over rocks or anything it is so rough and beats the shit out of me. The forks also don't rebound all the way. I can push them down and they don't come all the way back up unless I pull them up. Is this caused by a weak spring or something? I just replaced the seals not long ago and filled with the correct amount of oil

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Your forks are binding due to improperly tightening the front wheel. I've seen this a lot. I put the axle in, tighten the clamp an the far side, bounce the bike a few times, tighten other side

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Have you tried winding some compression and rebuild out ?

when you say you pull the bike up to get them to rebound, do you mean the last couple of inches ? 

 

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Its normal to have two inches or so of fork sag.  I like a little less but usually you're between 40 and 60mm difference between where they sit with you on the bike and the bike on the stand and forks fully extended.

Those forks also have a lot of rebound damping which can hold them down in the stroke and make them feel harsh.  I'm running mine with three of the original seven rebound face shims.  I also installed 11mm longer springs from an 05 KX to help keep the front end up.  You may not benefit from the longer springs and increased preload but you could definitely improve fork action with revalving.

Do you jump the bike or just ride woods and trails?

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Your forks are binding due to improperly tightening the front wheel. I've seen this a lot. I put the axle in, tighten the clamp an the far side, bounce the bike a few times, tighten other side

I'll try that tomorrow
Have you tried winding some compression and rebuild out ?
when you say you pull the bike up to get them to rebound, do you mean the last couple of inches ? 
 

Could you explain more and yes

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Its normal to have two inches or so of fork sag.  I like a little less but usually you're between 40 and 60mm difference between where they sit with you on the bike and the bike on the stand and forks fully extended.
Those forks also have a lot of rebound damping which can hold them down in the stroke and make them feel harsh.  I'm running mine with three of the original seven rebound face shims.  I also installed 11mm longer springs from an 05 KX to help keep the front end up.  You may not benefit from the longer springs and increased preload but you could definitely improve fork action with revalving.
Do you jump the bike or just ride woods and trails?

Typically how much is revalving and woods and trails

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I don't know what a shop would charge.  I do it in the garage.  Very easy on those forks. 

I would tell you to pull one face shim from the mid valve compression stack, three face shims from the rebound stack and leave the base alone.  Might as well disable the bladders while you're in there too.  The only tricky part about the job is removing the peen from the mid valve nut.  There aren't a lot of threads on the stem so you have to be careful here.  I would guess a shop would charge at least $200 and who knows if they get it right or if its no better or even worse than they are now.

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19 hours ago, Yz_Smoker said:

 

When riding my kx250 over rocks or anything it is so rough and beats the shit out of me. The forks also don't rebound all the way. I can push them down and they don't come all the way back up unless I pull them up. Is this caused by a weak spring or something? I just replaced the seals not long ago and filled with the correct amount of oil

 

Also, did you replace the fork bushings? 

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This guy explains it well, I had a slight bind that was causing your symptoms
 

Just tried that and still is the same
Also, did you replace the fork bushings? 

No

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If you simply finger tighten the pinch bolts does it still occur?  If so then something higher up 

Edited by Chris Gibbons

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Hey so just another idea to thrown in. Especially since you just did the fork seals. I don't know if your bike has dual chamber forks or not but I just did a fork seal on my klx450 two weeks ago, which has dual chamber. The manual has a specific paragraph about having to bleed air out of the inner chamber after you fill with oil. It then says to let the piston rod fully extend, if it has to be pulled out at all then there is air in the chamber and it has to be bled again. Not sure what forks you have, or if this applies to single chamber as well. But at least from what I read in my manual for dual chamber forks a couple weeks ago it sounds like maybe air stuck in the inner chamber. 

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If you simply finger tighten the pinch bolts does it still occur?  If so then something higher up 

Still the same

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20 minutes ago, Yz_Smoker said:


Still the same

what i would do next is take the front wheel off and action the forks by hand, and assuming it is still being weird then probably time to get back inside them!

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3 minutes ago, Chris Gibbons said:

what i would do next is take the front wheel off and action the forks by hand, and assuming it is still being weird then probably time to get back inside them!

and you might find one side is good, the other not...

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17 hours ago, Chris Gibbons said:

what i would do next is take the front wheel off and action the forks by hand, and assuming it is still being weird then probably time to get back inside them!

 

Yes, remove the wheel and put the bottoms of the forks on a piece of wood or something similar to protect them, then try actuating the forks.  If they still stick you have some internal problem/bent fork, etc.

 

I use the zero point aligning method:  http://gamma.nic.fi/~kalevin/front_axle_alignment.pdf

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If you're going that far might as well loosen the pinch bolts and drop the forks out of the clamps.  Then you can pogo on them against the floor and see how they work.

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Yes, remove the wheel and put the bottoms of the forks on a piece of wood or something similar to protect them, then try actuating the forks.  If they still stick you have some internal problem/bent fork, etc.
 
I use the zero point aligning method:  http://gamma.nic.fi/~kalevin/front_axle_alignment.pdf

Just tried that and they work fine and smooth

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I kind of worded my problem wrong. There is like two inches of sag, then I can push them down and rebound fine. But then I can pull up on the handlebars and extend the forks all the way and they'll stay like that till I slightly push them and they'll return to normal sag.

 

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