Rode it without the rollers and the noises went away. Will replace the lower roller today and make another post.

 

Mine problem isn't just a noise, though. I can Feel it. Under hard acceleration, it FEELS like it's skipping. I can also hear a hard click.

 

Yeh,.. along with my previous post I can say that I DEFINITLY felt it also. That is what scared me the most.... the noise and feel,.. just like the chain was skipping on the front sprocket! or first gear was skipping and waiting to gernade.
Hope this helps.... mine went away though.
Does your do it all the time?

 

I noticed the same noises (and feeling) coming from mine and thought it was the lower roller. I checked it against two 400ex's and they were loose too so I thought it was normal. After reading this post, I went back and checked again. My lower roller was so loose and the chain a bit loose that the chain was grabbing the lower skid plate. I thought my transmission was going out in both 1st and 2nd gears. A new lower roller from Moose (the large size) seems to have fixed it.

 

For what it is worth, my top roller was frozen also. the Yamaha bearings were shoddy. They were not a good sealed bearing. The bearings from in-line skates fit perfectly. No more noises.