SR50 Carb clutch problem

[zafirovski96]

Hi, maybe it's going to be funny what i am asking but i've noticed something like grinding noise coming of my transmission case when on idle , on aprilia sr50 carb model ( piaggio hyper 2 engine) especially from the rear , clutch area. Nose goes off as soon as you start riding. Also there are some pretty noticeable  vibrations during low speed riding. I am using giannelli rekord exhaust with 4.3 rollers. Everything else is pretty much stock on the bike. 

If someone can help, that would be more than helpful for me. 
Thanks.

[90GTVert]

Have you taken the cover off and inspected the CVT at all? If not, I'd start there. Could be simple like something loosened up and needs to be re-torqued. If it goes away under throttle, that makes me think of broken or missing bushings on the ramp plate or possibly a clutch issue.