I have a 06 YZ450F. I was riding my bike a couple weeks ago and the front forks completely lost their dampening. It felt like I was riding on the springs. I took the forks home and completely rebuilt them with an OEM Kit. I even replaced the cartridge seals and the ICS seal. I put the forks back together and everything was working great for about an hour and again I lost the dampening. Every thing is new inside the forks and they fade out. I took the forks apart again bled the inner chambers just to be sure and same thing happens in about 45 mins of riding. I'm stumped.