2001 xr400 fork disassembly

[catsxr]

Can anyone tell me how to take my forks apart for the first time. I know how to remove the springs but not positively sure how to set the clickers for rebound after taken apart. Want to clean them and change oil. Is there anything special, like bleeding the cartridge that has to be done. Is there anything that I can do to the compression valve while apart that can make the forks take sharp hits better?? I know this is alot so thank you

 

[BBD]

Get a manual for your bike, Clymer or Honda factory. Either one will show you and tell you how to do the forks and what tools you will need. The manual will pay for its self by letting you work on your own bike.

 

[James]

Past getting the spring out, I think you just dump the oil, refill, pump the damper to get the air out, set the oil level, and go. There is a trick to setting the rebound clickers but it has been a while since I worked on XR400s. I think what I did was turn the rebound out to full soft, then turned it in the number of clicks it is supposed to have for total adjustment, then two clicks more for safe measure. You then turn the cap down onto the rod until it lightly seats. This should insure that you have the full range of rebound adjustment. If you install full soft, the you won't have any adjustment and from what I remember, if you turn the adjuster in too far with teh cap off, the rebound adjuster will start leaking (had to replace one myself).

As far as further disassembly of the forks, you will probably need a damper holder and/or an impact wrench to get the center nut out of the bottom and that will allow you to take the damper completely out of the bottom tube. I don't think this is necessary for regular fluid changes and cleaning.

I have a Clymer manual for the XR400 and I followed it step by step when disassembling my forks, changing oil, and reassembling. The pictures are helpful. I sold the bike and would be glad to let the book go fairly cheap..email me if you are interested.

 

[DEANSFASTWAY]

Yeah get a manual it will also tell you how to adjust the valves & stuff. There is a trick to centering the rebound adj on the damper rod . If not done properly you will be out of adjustment range and in the worst cenario your forks could come apart . Good fork oil level is about 120mms , might want to try to preload the springs abit to get the front end abit (little) higher or if youre heavier maybe a bit firmer spring replacement if thats what you like . If you know how to revalve you might want to remove a little bit of the HSC stack but if youre not experienced with that maybe youd be better off seeking help. GOOD LUCK

 

[James]

Dean is right about the 120mm, that is where I ran mine....I am 230 lbs. Most of my "sharp hits" came from blowing through the suspension.

Also, by using the reboung adjuster method I described, you are sure to get the best possible/deepest engagement of the cap with the damping rod threads while still having the full range of rebound adjustment.

 

[catsxr]

James & Deansfastway,......Guys, Thanks a lot for the specific info and your experiences. I hate it when some people say to just get the manuals, dugh, why didn't I think of that. I have never had luck with the manuals although the pictures probably would be helpful. It's just that for all the "tricks" you can do to the XR's everybody talks about till they are blue in the face, like removal of the snorkle and re-jetting, head pipe welds, air filters etc. I'm surpized there is such a lack of things to make your bike more rideable, ie. suspension tricks that a home wrench with the desire can play with. James... a few posts after this one, you guys kicked around the effects of stiffer springs and oil level and your depth of hashing it around made my head spin and made me think. I like that. Is there any posts or places you know of that goes to the in depth disscussion about re-valving your forks? I'd like to get some background. As for "sharp hits" and blowing through the travel, I have a SRC brace on my bike and I have a tie wrap around the tube to see just how much of my travel is being used and after really smacking a hidden root that shook my teeth, I've looked down to see that only half os the available travel had been used so it's not bottoming.

 

[James]

How much do you weigh catsxr? You must be a light weight to not be bottoming the XR or something is wrong.

Make sure your springs are correct. There is a spring calculator on Racetech.com that I used to buy all of my springs. There is also one at http://www.mx-tech.com/core.asp but last time I looked, it had mostly MX bikes. Check your oil level and if it is in the 4 inch/120mm range, then I think you can lower it to 4.6 inches to allow more travel through the suspension. I think this measurement is taken with the springs removed and fork tubes compressed...again, would be best to consult a manual and don't do this until somebody can verify it or you look in a book. I will try to remember to look up the oil level range in my book when I get home and post it here....I will also check to see if it specifies measuring the oil level with compressed tubes or not.

Also, double check your clickers. I think My XR had about 15 rebound and compression clicks both ends and the standard setup was about middle of the range. I let the owners manual go with the bike so I don't know the exact numbers anymore.

Make sure your fork tubes are installed properly. Here is a good article on installing forks: http://www.mx-tech.com/downloads/FORK_INSTALLATION.pdf

There is also lots more good info here: http://www.mx-tech.com/downloads.asp

Even if the manual doesn't give you all of the inside tips, it will give you all of these specifics we are guessing at. A manual is cheap compared to getting hurt or damaging your bike from bad advice. I always double check advice I get here and I would recommend you double check ours. Also, if you make a change, I am sure you know to go slow until you know all is good with your bike.

This is a great thread on suspension:

http://dirtrider.net/forums3/showthread.php?threadid=5419&highlight=large+port

I have run many searches on "valving", "Racetech", "shims", "gold valves", etc. etc. All I can say is run the searches on teh suspension forum and see what you get. I haven't found many outside sources yet. Eric Gore's book gives some good info and I have learned a lot by studying Race Techs Valving charts that come in their kits.

Hope this helps some.

 

[James]

Recommended oil level is 4.6 inches measured from the top of the tube, forks fully compressed, damper rod pushed down completely (after bleeding air), springs out. Unfortunately, this book doesn't give the oil level range, that was the factory service manual, but I am quite sure it can go at least .5 inches both ways and now that I think about it, I was running 3.75 inches just before I sold it. Rebound adjustment range is listed at 12 clicks so turn your rebound adjusters out to full soft (counterclockwise until they lightly seat), turn them back in 14 clicks, and then reinstall the caps. This will leave you 12 or more clicks of adjustment and use as much of the threads in the cap as possible to hold the damper. Recommended setting is 3 so turn clockwise until they lightly seat and then back out 3 after completely installed.