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2002 xr 250r fork rebuild

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I have a question. How much fork oil do I use in each fork for a rebuild? I have new fork seals in I just need to know how much oil to use. Can't find it online. And one last question. Is the hex head on the bottom of the fork an adjuster for the force of the shock? Any help is appreciated Thanks

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I have a question. How much fork oil do I use in each fork for a rebuild? I have new fork seals in I just need to know how much oil to use. Can't find it online. And one last question. Is the hex head on the bottom of the fork an adjuster for the force of the shock? Any help is appreciated Thanks

 

What you want to go by is the oil height in each leg. Usually, fork oil comes in 1 liter bottles. Most likely you will need a little more than 1 bottle to fill both legs to the correct height so I'd say to get 2 liters just in case. You should look to download a manual so you can get the proper height info and the procedure down. You have to fill the forks up, work the damper up and down to work any air bubbles out, then actually take out oil until it is at the correct height from the top. Again, best off using the procedures in the manual.

 

I'll admit I have a 400 and not a 250 but I'm pretty sure that would be the compresion damping adjustment. Clockwise (or towards the "H") will make the forks move slower through the stroke and give a firmer ride. Counterclockwise (or towards the "S") will let them move faster and give a softer more compliant ride. It's not the actual Hex head you turn but the slotted screw on the bottom. You will feel clicks every 1/4 turn or so and they should move easily. Don't force anything.

Edited by michigan400
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Google "flight of the platypus". I know it sounds retarded but that's where I downloaded mine. I have an 02 xr250r. The flat head screw inside the hex on the fork leg is the compression adjustment. There's no rebound adjustment on these bikes. CW for harder, CCW for softer. As for the oil level, I think I set mine at like 78mm from the top of the tube, I think somewhere around 82mm-85mm is stock. I run 10w oil also. I race mine so I've got it set up fairly stiff. You'll want 5w oil and the stock oil level if you trail ride and are looking for a plush ride. I'll check my manual when I get a chance to make sure on those oil levels.

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Google "flight of the platypus". I know it sounds retarded but that's where I downloaded mine. I have an 02 xr250r. The flat head screw inside the hex on the fork leg is the compression adjustment. There's no rebound adjustment on these bikes. CW for harder, CCW for softer. As for the oil level, I think I set mine at like 78mm from the top of the tube, I think somewhere around 82mm-85mm is stock. I run 10w oil also. I race mine so I've got it set up fairly stiff. You'll want 5w oil and the stock oil level if you trail ride and are looking for a plush ride. I'll check my manual when I get a chance to make sure on those oil levels.

I race also and that's why I'm looking to make the front end more stiff. Bottoms out too much for me I have 10w. Il check more when I get home. And when I put the oil in should i turn the adjustment too soft?

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One thing that hasn't been mentioned is fork spring rate.  If you don't have the correct springs for your weight, nothing you do with oil weights and compression adjustments will help with bottom-out.

 

Here's a basic chart with approximate fork rates vs rider weight:

http://www.4strokes.com/tech/honda/sprngrts.asp

 

Racetech also has a decent rate calculator.

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When you change the oil you have to back out the compression clickers to full soft.  When you add oil you need to have the fork compressed with the spring out.  checking the oil level with the springs in, since they take up volume, will give you a false oil level.  You will have to take the fork off the bike to take the cap off and add oil.  You don't need to have the clickers backed out for this. 

 

Depending on how much you weigh and what pace you ride at you might be able to step up to a higher spring rate.  I'm 210 lbs and ride a high B-Class speed.  If you go to RaceTech they don't offer a spring for the XR250R BUT... I was able to do some digging and research and was able to find a higer rate spring that has the same physical dimensions as the stock XR250R spring. ... :thumbsup:   Go to this link http://www.racetech.com/page/title/FRSP-RT%20Fork%20Spring%20List and look up the FRSP 324546 fork spring.  Its a 0.46kg/mm spring that is a direct drop in replacement for the stock 0.39 kg/mm spring.  This was the only spring that I could find that had the same dimensions and was closest to the rate that they reccomended.  I've been more than happy with my front end and you can really send it off into a corner and not have to worry about the fron end tucking near as bad as it used to. 

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Start with the recommended weight of oil in the manual.  Chances are, this will give you perfect rebound damping.  Early damper rod forks work well with ATF (6w).  XR4 forks use a much lighter fluid.  What does the manual specify for your forks? 

 

Things to consider for rebound damping are: 

1.  Without a rebound adjustment, rebound damping is adjusted by fluid viscosity. 

2.  Too light a fluid will cause your forks to fully extend and hit their stops when you hit cantaloupe-sized rocks at 50mph.  

3.  Too heavy a fluid will cause your front wheel to wash out on turns and slants because the suspension cannot react quick enough.  

4.  Fluids can be mixed to get the perfect viscosity.

 

The compression damping can be increased if the suspension feels too soft for your terrain or weight, but if you're doing this, you probably need stiffer springs along with a slightly heavier fluid to match the spring rate. 

 

IMO 10w is too heavy for XR forks unless you have some very stiff aftermarket springs.

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I have a custom set of springs in mine .45kg/mm, and a 8mm spacer, oil level @ 80mm, lightly modded valving. Compression-wise the fork is good,could go a little stiffer on the compression, rebound-wise the action is too fast. I can hear and feel the fork top-out of a jump. Currently using 5w oil, will be switching to a 7w oil here soon. 

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 I can hear and feel the fork top-out of a jump. Currently using 5w oil, will be switching to a 7w oil here soon. 

 

That's a good place to start.  You want just enough rebound damping so it doesn't top-out.

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That's a good place to start.  You want just enough rebound damping so it doesn't top-out.

 That's what I'm shooting for. ;)

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I had an 03 XR250, I raced expert level desert and A enduro on mine.

Mine was 100% stock except I removed the air box snorkel and the small exhaust baffle.

I did replace the fork springs with stiffer.

I also had 1994 and a 1997 XR250s, both those bikes were stock too but I put small spacers on top of the fork springs.

I was 225lbs then.

I always did pretty good usually top 10...  top 20 every time.

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