Any simple (cheap) mods for forks while replacing seals???

I have to do a seal job on my 99 400 this weekend and I am wondering if there are any tips or mods I could use while I have them apart? Like oil weight , Height shim removal... I weigh about 165 and I am a vet class rider trail and MX THANKS I am also wondering if there are any fork seals that last longer than stock.?? :)

I've had a lot of luck using seals from White Brothers. They seem a little tighter - more "stiction", but last a lot longer. I've put White Brothers seals in forks for a lot of other people, too and they were happy with the life. The worst I've used were OEM seals. They start leaking again very quickly, even when you keep them cleaned.

Definitely recomend against OEM seals. Got some aftermarket seals from my Yamaha dealer cause even they said OEM leak. Agreed, there is a little more stiction, but no more leaks.

I strongly reccommend OEM !!

I've done well over 100 pair of forks, using only OEM , I had only 1 fork leak (3 weeks ago), and that was after the guy rode it for a while and abused it pretty good.

What is REALLY important is how well you clean the internals during rebuild. If you do a dump and flush, you can expect problems. A very thorogh teardown, I mean, base valve, midvalve,shims, I mean EVERYTHING taken apart and cleaned thoroghly (I use a 2 part cleaning method). This is the only way to get all the sludge and junk out. I know this is time consuming, (I can post a detailed procedure if anybody would like one)but I strongly beleive this makes all the difference.

Take Care, John

<font color="navy">I have changed the seals twice now on my 2000 YZ426. The first time, I installed the OEM seals, and they only lasted a few rides. The second time, I installed the seals for a 2000 KX500 in my 426 after reading a post on this subject recommending this. The seals can be interchanged because they're the same size, however the seals for the KX have lasted WAY longer, even longer than the original seals.

I would give the KX500 seals a try in your 400(granted the forks are the same diameter as the 2000 YZ426) I'm VERY glad I did!

I just finished servicing my forks, here are a few tips. I had extra bushings on hand to replace any that were worn, 2 were worn to the point the teflon was getting thin. I also went with White Bros seals and dust covers. I installed the White Bros fork bleeders which will make bleeding the fork pressure off a 2 second deal instead of a 5 minute deal. Make sure you have the 14 mm allen head socket to remove the base valve before you start, I can tell you they aren't readily available at any of the stores I went to. Also, when your done, put a little grease over the fork seals before put on the dust cover, this will help keep crud out of your fork seal. As far as mods go, unless you bought a Race Tech gold valve kit, your pretty limited. You can try a different oil level, I think book suggests between 80-135mm. Just clean everything up real well, inspect everything and replace the worn parts. I talked to RG3 and they said you shouldn't use anything lighter than 5 weight oil in forks, so that's what I used in mine. Oil lighter than 5w is generally for the shock.

Good luck,

Pat

99 YZ400

Lemme ask one thing.....if OEM seals leak after only 2 rides....why haven't you had leaking problems as of your second ride from the bike being new?

Granted, the WB seals may be better yet, but OEM are not THAT pathetic. You should be able to get almost a full season of long riding out of a pair of seals.....at least I have been able to before with my KX. My KTM's blew after 6 months, but only after some severe bottoming. (I mean bone jarringly nasty bottoming!)

Let me back step here for a second, I installed white bros seals this time but that is because I bought all the bushings from them. I had OEM seals in there for a year with no problems. I think if you keep the area under the dust cover clean, they, or any fork seal will last a long time. Once in a while I pull the dust covers down and spray some contact cleaner up there and put a little bit of grease in there to catch the gunk before it hits the fork seals.

Pat

seals from a 97 and up honda cr 125 fit the yamahas too..thats what i run..pro-action recomended them...they have a little bit stiffer spring...i usually tear my forks every 5 to 6 races and the seals always look good...but i clean them after every ride!!

My vote is for OEM. Installed with the correct tools without beating the crap out of them to get in.

Originally posted by Chris Slade:

Lemme ask one thing.....if OEM seals leak after only 2 rides....why haven't you had leaking problems as of your second ride from the bike being new?

Granted, the WB seals may be better yet, but OEM are not THAT pathetic. You should be able to get almost a full season of long riding out of a pair of seals.....at least I have been able to before with my KX. My KTM's blew after 6 months, but only after some severe bottoming. (I mean bone jarringly nasty bottoming!)

<font color="navy">Chris, the stock seals did not last long either. They started leaking after approx. 20 hours from when it was new. Maybe because I'm a 200 lb guy, I'm not sure. I can tell you, however, that the Kawasaki seals have lasted this entire season with zero problems.

If you have had different results, that's great. It seems Kawasaki's seals are just holding up better.(your <u>KX</u> 250 lasted a full season)

I'm simply sharing my opinion on the topic. :)

Ride Hard

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