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XR250 fork service

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So on the project bike i thought i would t least put new oil in forks so i get a picture of the suspension setup/condition from a known point.

I've taken the cartridge out of each side, and 1 fork tube slides really easily up & down, the other binds a fair bit half way through the travel.

Does the binding means its not straight or can it be a tight bush ?

 

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Bushings don't usually get tighter. If anything, their wear causes flexing in the forks. I would guess the problem is a bent tube. Check the lower/outer tube for dents/evidence of damage that could be heavy enough to have deformed the tubes i.d. in a certain spot. I would think any deformation would be easy enough to see with a flashlight.

Edited by Trailryder42

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Hey FFMan. PaydayGabe here.

The binding means you have an issue! Lol.
Either or, a bent upper tube or tight bushings.
Each leg has 2 bushings.
One is at the lower end of the fork tube(slider) and the other is at the top of the lower leg just under the fork oil seal.
Confused? Not really. Simple actually.
Your forks are going to need a rebuild so plan on some parts.
First: separate the upper from the lower. Be sure the Allen head bolt on bottom of the lower leg is removed. Be sure the fork seal spring clip is removed. Hold the lower leg stationary, , firmly grasp the upper slider and give several sharp upward pulls till the upper slider separates from the lower. Kinda like a slide hammer in effect.
Now for your inspection.
Give everything a really good clean. I love brake cleaner, the cheapest you can find.
Look closely at the bushings for strange ware patterns. Replace as needed.
Take the chrome upper slider and place on the smoothest/flatest surface you can find.
Kitchen counter tops are great for this.
Give the slider a gentle push, , should roll smoothly across the counter top, ,hopefully.
If so, your golden.
If not, more drama.
Let us know what you find. G.

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thanks for the advice - i had just looked at the manual and decided on the same course of action.

If bent then either i try and get a leg, or go for an xr400 fork conversion - i'll update tomorrow when i get more time on it

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Outstanding, if you have a bend/bow condition I have a solution for you. Much cheaper than the alternative. G, in Vegas.

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That should have no effect on the lower sliding over the upper tube. The triple clamps should be tightened in a progressive order.
What I do.
Install a leg, , gently tighten the lower clamp. Grab a strait edge ruler so you can measure the exposed tube in the upper clamp if needed. 5mm, 10mm, whatever.
This measurement will have an effect on how fast or slow the front turns in. Your preference.
Install the other leg, duplicate the first measurement. Gently tighten the lower clamp.
Everything should match equally. Now progressively tighten the lower clamp then the upper. I use a kris-kross pattern. Lower to upper, and never go over 15ft/lbs. , that's it. G.

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so curiosity got the better of me and i just pulled apart both fork legs.

laid the binding one on a long builders level and i can't detect any bend, so can i assume the bushes were the issue - it had been standing for a while outside.

thinking i should get this and put it all back together ?

 

http://www.ebay.co.uk/itm/151708905032

 

Edited by FFMan

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Great news. That's a really good price for all those parts. Get new seals and a good oil.
The weight is up to you. The heavier you go the slower the forks work.
I run 10w here in the desert SW USA. Some folks run Automobile ATF.
Depends on the terrain and weather temps where you are. Take your time and have fun. Super clean everything and do one leg at a time. Cheers, G, in Vegas.

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Yeah,, order everything up front first. Then you can assemble without interruption. It's fun.

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do i need the dust seals and gaiters or is it either but not necessarily both ?

I run skins on the xr400 but not sure i'm that keen as when they get wet they'll hold the moisture against the fork leg

 

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Definitely have the seals/dust seals. That's a given. Required parts.
Now, the gaters are up to you.
I've read of severe corrosion on the upper tubes from road salts and grime being hidden under gaters. Especially in UK. Again, your call. I, , personally like them. Reminds me of the old enduro bike's I would daydream about when I was younger.

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