Rear sprocket damper sponge thingy ?
 

Can anyone tell me what that spongy damper ring thing is for between the rear sprocket and carrier on an xt600e 4pt ?
I see a lot of carriers without it on; Is it needed?
Cheers

Are you taking about the separate rubber pieces that fit inside the cush mount (aluminum thing with splines)? If so they're there to absorb the shock from the chain, they are definitely needed or you will wear down the cush drive and need to replace it. More dedicated dirt bikes don't have them but for the street it'll tear stuff up. I don't think it'll even fit without them right?

I don't mean the cush rubbesr inside the hub.
it's outside between the sprocket and sprocket carrier, listed as "Plate 1" on the parts list.
I called Yamaha and the guy didn't know what it was for either. :rofl:

I think its to "seal" the sprocket carrier, and perhaps minimize vibrations, like the one in the front wheel that fits outside the hub.

I thought it might be to keep dirt out. might be worth getting a replacement then, thanks.

I read the front one was to stop noise from vibrating spokes under braking!