Need rear shock advice

[adrenalinejunky81]

Is it worth the time and $ to have the stock rear shock revalved? I know anything would have to be a huge improvement over stock 89 KX5 equipment, but from what I see is the rear shock has some serious deficiencies. Has anyone found a newer shock swap that fits/works? Oh yeah Im about 145lbs and I dune it mostly. Tired of gettin left behind!! Thought it was 100% my fault, then borrowed a 250f. Now its obvious that its more like 80% bike and 20% me. New take-off shocks are cheap on ebay, its just findin measurements thats hard.

[Platypus]

When was the last time you had the suspension serviced?  That's a good starting point.  Springs and certain internals do wear and need replacement over time.  A bike that has sat for a while will need basic suspension service (replace fluids / recharge shock).  Have you done any basic setup to it?  Such as adjusting the sag?  Start from the beginning because you will have to do this stuff anyway if you go for revalving and all that good stuff and it could end up saving you money on something you don't need.  You can get basic service done on it for 75 bucks or so and most suspension guys will set it up based on your weight, riding style and level of skill.

[adrenalinejunky81]

I know it looks abused in that pic buried in mud, but I assure you its not. It handles most things fine, but other times the rear ends unpredictable. Id prefer to find a newer shock/spring and toss the old one in the trash where it belongs. Id hate to put $300 into a shock Im still not going to be happy with 

[Platypus]

My rear end can be unpredictable too.  It can send me swapping through whoops at speed and scare the crap out of me or send me flying.  I'm pretty sure most of the time it's body position.  Anyway, answer some of those questions and you might get some help. 

[adrenalinejunky81]

When was the last time you had the suspension serviced?  NOT BIG ON DONATING MONEY TO THE LOCAL "MECHANICS" IM MORE THAN CAPABLE OF BREAKING IT MYSELF. ID ACTUALLY BE SURPRISED IF ANY SHOPS WOULD TOUCH A BIKE THIS OLD That's a good starting point.  Springs and certain internals do wear and need replacement over time.  CHANGED OIL LAST YEAR, FRONT FORKS WORK AND LOOKED FINE A bike that has sat for a while will need basic suspension service (replace fluids / recharge shock). ITS NEVER SAT Have you done any basic setup to it?  Such as adjusting the sag?  IM 5'6", NOT A WHOLE LOT OF ROOM TO SET IT, NOT BOTTOMED BUT MAYBE LOWERED A TOTAL OF AN INCH OR TWO? Start from the beginning because you will have to do this stuff anyway if you go for revalving and all that good stuff and it could end up saving you money on something you don't need.  THEN WHO DOES EVERY REVIEW ON THIS BIKE (AND EVEN WHEN NEW) COMPLAIN ABOUT THE SAME THING IVE NOTICED?? THE REAR SHOCK NEEDS TO BE CHANGED WITH SOMETHING UP TO NEWER SPECS You can get basic service done on it for 75 bucks or so and most suspension guys will set it up based on your weight, riding style and level of skill. AND THIS WILL FIX THE SHOCK "SPIKING" EVERYTIME I LAND SOMETHING OVER 4'? NOT FUN WHEN COMING OVER THE TOP OF A DUNE. ITS SET PERFECT FOR EVERYTHING ELSE AND I HAVENT SEEN ANY IMPROVEMENT I LIKED FROM MESSIN WITH IT. 



Bikes arent supposed to bounce the rear up when landing. My friends watching have told me the same thing. Someone out there has to have swapped in a newer shock. Am I gonna have to be the first???

[bigborefan]

I had an 88KX 250, and if I rememeber it handled pretty good. However, your shock could just be worn out. They do have aluminum bodies and lots of soft aluminum parts. An 89 is getting up there in age. You won't know untl you take it apart or go to a suspenison guy. I would think a shock off of a newer 500 would bolt right on, I would say anywhere from 88 to 2004 should be the same length and bolt right on. At 145lbs you are probably OK with stock springs as well.

The 89 fork was one of the best forks out there as well, in its day anyway.

[Platypus]

Bikes arent supposed to bounce the rear up when landing. My friends watching have told me the same thing. Someone out there has to have swapped in a newer shock. Am I gonna have to be the first???

I guess so.

[GDubb]

Of course a shock ABSORBER isnt supposed to bounce on impact... take the bike to a REPUTABLE bike shop and have them check it out. If its fixable they can fix it, if not they should tell you so.  I think by the time 1989 rolled around Kawasaki already had a pretty darn good idea how a shock is supposed to work and would think that the stock equipment wasnt just junk. If the shock body and shaft are still in decent shape there is absolutely no reason why a good rebuild wouldnt get it working like new, especially for a 145 pounder like yourself. In 1989 they were getting much more than just 4 feet of air so in proper working order the stock shock should be more than capable. We could use hughes' opinion here, he has totally rebuilt an 87 KX500 and should have the better idea on how they hold up.


-G

[hughes]

I agree with bigborefan I think the shock is just worn out or improperly serviced. My shock on my 87 500 worked great at any speeds and terrain I could throw at here in GA. The rear end always tracked straight without swapping ends. My shock was junk when I bought the bike. I searched the world for new parts for the shock before I rebuilt the unit. Sounds like your shock has no rebound damping, oil is blowing by the piston and bypassing the shim stack (the shims wear and fatigue) and is kicking the rear end up, or the shock is not compression properly (air in the shock). The shock has a special coating on the inside to help prevent wear as the piston goes up and down, an 89 model bike? That coating is gone. The most important thing during shock rebuilding is making sure no air is in the shock. Any air bubbles and the shock will not perform. Good luck getting it taken care of.

[moburki]

I would highly reccomend a revalve and proper spring. I just did it to my bike, front and rear, and the bike is soooo much more fun to ride. I believe the rear spring valving is quite soft in both comp, and rebound. Forks are a must, at least heavier springs (unless youre really light). I do always revalve and spring my race bikes, and it's the most bang for your buck you can get. I believe there is a forum sponsor that's reputable (in AZ?) and I will reccomend talking with Nick at Pro-Valve MX in CA for susp. needs.
GL

[Hillclimb#42]

You definately should take it to a person who does it all the time. It is alot more involved than just adding oil, or a seal. If the bike acts like a pogo-stick, then it is completely blown already. It should always come up slow, not just as fast as it goes down. The ergonomics are better on newer bikes and the angles of the shocks and all that are different. They are alot lighter now too, but it sounds like you are running on a blown shock.