Front Fork Question

[dmg]

Hi All! Awesome site!

This is my first post.

I have been riding for years, had a 89 KX 250, and now have a 92 KX 500. I love everything about the bike, except the suspension. I am pretty sure the bike is bone stock. I am actually fairly sure the front tire is original (just grabbed a new one last night).

I decided I was finally going to do something about the suspension. It is mush. I took the front forks off, and was going to replace the oil, because I am sure that has never been done. I picked up some of the 7W BelRay fork oil and shock oil. When I had the forks off the bike, I tried to compress one fork just by leaning on it with my weight. I was able to push it to within 2-3 inches of the bottom. This doesn't seem right to me. It also rebounds fairly quickly, so I know the oil is bad.

The forks have never leaked. I weight around 200lbs. I ride desert and dunes.

I would love to bring in the forks and have them rebuilt by someone, like I did on my 250. That was the best money I ever spent on that bike. Now, I have more time than money, so I am trying to do it all myself. I am pretty handy, but I have never done this before.

Any thoughts?

Thanks,

Darin

[jfabmotorsports.com]

Race Tech has video's on how to...fork and shock. Also, if you buy a valve kit from them you get the video free.   

http://racetech.com/

JFAB

[Hillclimb#42]

 have you stiffened both adjusters top and bottom? And its still full of oil? Oil doesn't go bad as far as I know.

[KXcam22]

The stock 92 comes with .39 kg/mm springs which are perfect for someone 100lbs or less.  I ended up using .46kg/mm which was about right for 200lbs.  I was unable to tune my 92 fork to acheive plushness AND no bottoming with the stock valving.  I got close with 10wt oil the .46 springs and raising the oil level to the max allowed (sorry I don't recal the level 100mm +/-).  I should have got the revalved or bought the race tech base valve.  The shock is also best with 10wt suspention fluid. Hope this helps. Cam.

[jfabmotorsports.com]

This is from Race Tech 

1992 Kawasaki KX500

Type of Riding:
 Desert / Enduro / Trail
 

Gas Tank Size:
 Standard Gas Tank
 

Rider Weight (without gear): 200  lbs 

Type of Riding: Desert / Enduro / Trail
Rider Weight: 200 lbs

FRONT FORK SPRINGS
Recommended Fork Spring Rate: 0.452 kg/mm (use closest available)
Stock Fork Spring Rate: .377 kg/mm (stock)


REAR SHOCK SPRING
Recommended Rear Shock Spring Rate: 5.62 kg/mm (use closest available)
Stock Shock Spring Rate: 5.4 kg/mm (stock)

[KXcam22]

I screwed up.  5wt oil for the forks, Kayaba 01.  Cam.

[DoldGuy]

DMG,

Great information & knowledge from Racetech as JFAB mentioned and KXCam was on with the spring rates. Fork oil does break down and you loose comp and rebound dampning (we used 2.5 wt fluid to keep it consistent when it heated up). If your forks compress that easily, check your cartridge seals (racetech info will show you) when worn you will lose alot of your dampning effect and the bottoming cones do not work as they should. I had an 92 KX 250 with low hours and the seals were leaking, replaced them, stiffer springs, and longer bottoming cones with oil height @ 110 mm and I loved these forks (relatively plush on small chop, held well on the face of jumps & very hard to bottom), but the best part is obtaining the Knowledge on how to service the forks to set them up for what YOU want, and the Racetech info will give it to you with a relative small investment in tools (cheaper than a reputable Company revalve).

[dmg]

Looking at the prices of the parts almost makes me wonder what it would cost to send the forks and shock in to Race Tech. If it wasn't too much more than the parts would cost me, I would consider it. If I need to buy all the special tools, and the parts, I might as well have someone else do it.

Does anyone have any idea how much I would save doing it myself? I would like to, but if it is only a little more than MY total, I wouldn't mess with it. What would Race Tech cost if I bought in the forks and shocks off the bike?

Thanks for all the help so far.

Darin

[gwcrim]

Now don't quote me on this, but I asked Race Tech about rebuilding a set of forks on a '92 KX500.  I was told it would cost about $400.  That included new springs, setting the valving, and lowering them a bit.

Of course, I may have missed something but that's what I recall.

The local Kaw shop wants about $250 just to put in new seals and oil.  I don't do forks.

[DoldGuy]

http://www.racetech.com/evalving/english/Srchpr.asp?bikeid=687&manufacture=Kawasaki&model=KX500&year=1992&TABLEINFO=dirt&langname=english

Invest the $400 into a fork revalve, or invest $400 in yourself and a revalve? How many times has someone had a set of leaky seals?

$250 for a set of $20 seals and $15 worth of oil and a half hour later?? If you invest in yourself you will be monies ahead after the first time you change a set of seals.

Just my 2 Pennies

[GDubb]

I've always wanted to learn how to do my own suspension but fear of the unknown has always kept me from doing it. I should just do it, especially since I have a leaky seal right now plus I gained a good 30 lbs this last couple years. I've never even had the caps off my forks. It would be nice to have somebody there to walk me through it the first time but thats not going to happen.


-G

[Johnniespeed]

After reading this thread,I  know I would try it myself first. I have always had very good results, reading, learning and trying. As long as care and caution were used, the results should be satisfactory, the education would be valuable.
 If after trying, and the results were not acceptable, you could always have them done professionally and you still would have more knowledge that when you began.
  John

[Motorrad]

The best thing I have found for fork fluid on all my late model bikes... is
Mobil 1 synthetic ATF fluid...

it works out to be roughly 7.5wt. and has all the seal treatment stuff in it that would be good for fork seals, solvincy, and high pressure etc etc...

Works great in all my bikes.

[DoldGuy]

I have a seal weeping on the ole girl now. If there is an interest??? when I pull it down to put seals in, I will try to take some pics & post them (if I learn how to put them on here). I will not be doing a revalve, but I will try to get pics of the valve stack to give some type of illustration of what is involved in the "valving" of a set of forks.

[pmskreta]

Last Thanksgiving I took my suspension into Race Tech. They did the Springs, Gold Valves, seals and fluid. They set it up for me, 230 lbs. ride desert and a little MX in Vegas. I believe this is the best money I've ever spent on the Beast. The difference was Amazing.