Modern Vespa

Primavera 50 2T 2018
I noticed a strange rattling noise coming from my variator. It stops when it's on idle, I only hear it when I accelerate and when I release the gas on higher speeds. My Vespa has 9900km. I've already changed the rollers because I thought the noise caused by worn rollers but the noise still persist. Do you guys have any idea what can cause this? Or is this the normal sound of the OEM 6.4gr rollers?

Video:
https://youtube.com/shorts/SRdoZ3cDoh8?feature=share

The rattling should not be there.
I think it is the belt that is hitting the housing of the transmission.
Definitely does not have anything to do with the rollers.

Your ET2 did 9900km when you changed the rollers. Did you check the condition of the belt? No bits hanging loose? Width is still OK?

If not then it could be the tension of the belt is too low. It is the spring inside at the rear pulleys and the width of the belt that define the belt tension.

Today I will inspect the belt width thoroughly although there were no cracks on it, it could be the width. True, thanks! It will be much easier to locate where the noise came from with the variator cover taken off. Is it safe to start the engine, then remove the variator cover? I heard that it's not a good idea because there are bearings on the cover to support the pulley from both sides. Do you think this method could damage the variator?

No. Not in either order

Update: I removed the clutch drum and inspected the clutch centrifugal unit. The 3 pads on the unit had a really shiny surface which I know is not normal. I sanded it a little bit with sand paper (all the 3 of them) and cleaned them really well with brake cleaner. I also found out that the inside of the clutch drum was also too "slippery" and had a shiny surface as well, so I also sanded it a little bit. After all of that, I reassembled everything and voila, the noise gone. I never thought that this was the problem. I also inspected the belt and it's 18.5mm wide, is it Okay?

I'am sooo happy thanks for the replies.

Thank you for sharing your experience. Can be helpful for others having the same issue.

So it must have been a stick-slip phenomenon. The clutch not engaging smoothly.

You said it is a 2018 and it did 9900km. That is a low mileage for a 2018.
Are you the first owner?

I was so thankful when I found this scooter, because the previous owners not really used it that much. I'm the 3rd owner, I was surprised when I got to know that. But it's like a new one, except these little "adjustments" but I really like doing these kind of things because I can learn a lot from them. I never had a scooter before.

Your problem now solved I hope you will enjoy the rides.