Vibration..

[FastKX500]

Yea I have a 89 kx500, and When I start it and rev it, it vibrates alot, I think a little too much, I cant really notice it that much when im riding it, but it shakes everything on idle. anyone know what causes this?

Thanks
-Kayne

[SLEEZ]

Nah that's normal, I have an 04' and it shakes like an alcoholic going thru withdrawls.  The only cure for the shakes is to buy a four stroke, which I didn't want to do.

[mikesmith]

Check for loose or broken motor mounts,shim mounts that dont fit snug to the engine case when tightened down to the frame(hope that makes sense).Main bearings can pound the case out(oval) if its been reved to high with an out of balanced crank,try to wiggle/move the flywheel up and down for play.The pipe can make vibes if the springs are missing/weak or the washer between the cylinder/pipe is crushed and use high temp silicone on it that joint and check for broken pipe mounts(under the tank mount is the worst).And yes its a BIG bike so it does vibe alot by nature.

[kawdude]

My 94 had a worn bearing journal which cause a bad vibration.  The problem was I couldn't tell without pulling the crank out.

[teamgreen500]

I was recently told that I need to shim my motor "A New" every time I pull the motor.

Also, my bike barely buzz's at all. Balanced Crank...turns it into a big smooth Teddy Bear!

Manny

[mikesmith]

I forgot to mention to replace the pipe o-rings to.

[woodsy]

Manny:
What EXACTLY do you mean by "balancing" the crank?  Here in Michigan the group I ride with has been talking about someone in Arizona who does this.  Do you know who this company is?  When you say "very little" could you put a quatified number better then stock that it is? 50 %? 70%? and in what rev range do you notice the better improvement? I KNOW what I am asking is very difficult but we are trying to determine whether or not the cost would be worth it (do you know what the labor cost to have it done is - this is with us doing the complete tear down).
Thanks
Scott

[kawdude]

http://www.crankworks.com/

[teamgreen500]

Actually, the most important aspect of "Balancing", IMHO, is "Allignment". I notice it everywhere. A stocker, usually with 50-100 hours on it "Shakes" in the bottom and "Buzzes" on top. I hate BOTH!

My cranks are "Alligned" - ALWAYS- and "Balanced" almost never (Last real "Balancing" was on a Motocrosser-'91 KX5.)

Manny

[FastKX500]

yea its not that big of a deal, I mean it runs fine, and when im really flying It doesnt vibrate much, its just when i first start it up, shakes the kick starter and clutch and break levers pretty bad, and i have no clue where to start balancing the crank or w/e, im 16 its my first big bike