Vibration and Pick issue

[Jojimughal]

Hi,
Recently changed my pcx2022 belt with rollers(19g). Now it vibrate alot specially at low speed 15/16km/h.
Also when i give it full race/throttle it doesn't respond very well. It slowly speeds up. I did change the airfillter also. Any help appreciated.

[Conelite]

You changed the belt or the rollers? or both?

I want to say 19g is stock right?