Kx500 vibration

[kxraptor]

I have a '01 kx500 that I love dearly.What I dont love is the vibration the engine puts out.After a couple of hours ridin I'm toasted.I have Fassflex bars that helped a bit but I need more help.Please!!!

[tharden]

From what I have read the two main causes of vibration is the crank out of clock and it being a 500cc two stroke.

[hughes]

Worn main bearing could be an issue. Have you checked all the engine mounts?

[KXcam22]

If it really bothers you, you might have to get the crank trued.  It is my understanding that the crank QC is not as good as it could be so that some with a good crank hardly vibrate and other vibrate lots.  It did not seem to get better with later years. My 92 does not vibrate at all, other than being a 500.  As Hughes says, worn main bearing can also cause some (or all) of that.  It is important to use higest quality main bearings possible, last longest and tightest clearances. Cam.

[barryadam]

From what I have read the two main causes of vibration is the crank out of clock and it being a 500cc two stroke.

two stroke is not an issue.  The main problem is that it is a single cylinder which is inherantly unbalanced.  The larger the bore and stoke (displacement), the larger the reciprocating mass, and hence the larger the resultant unbalance forces.

The best you can do is have fresh main bearings that are within tolerance and an aligned crank.  As well as good motor mounting.  Could be worse.  Could be an American single pin crank V-twin.