New vistrom 650 2024

[EYAL400]

A noise like a ringing engine at 3000 rpm . what can it be ?

[Gert]

Too little info provided wrt your bike's current setup. Crashbars, luggage, sumpguard, other accessories fitted. It would be a process of elimination.
Since it is a new bike, still under guarentee / warranty, maybe it would be best to take it back to the dealer from where you bought it and let them follow up.

[Steve T]

Bit of rocket frag rattling in your exhaust can?

[Upt North]

Have you got Givi engine bars fitted?
Upt.

[EYAL400]

I didn't change anything on the bike. In the morning, when the mixture is rich in the first two minutes, this does not happen. only after that.

[Gert]

In reply to the "In the morning, when the mixture is rich in the first two minute" comment, to me that could be related to the fast idle system / cold start at work. When the fast idle cam is turned by the secondary throttle valve actuator, the cam pushes the lever on the throttle valve shaft causing the throttle valve to open and raise the engine speed.  Once the engine has warmed up, depending on the water temperature and ambient temperature, the fast idle is cancelled allowing the engine to resume idle speed.
Have a look at the discussionin https://www.v-strom.co.uk/smf/index.php?topic=41119.0

Or it could be related to the low idle rpm assist feature, which as you open the throttle off idle,  will add more fuel / increase the rpm. Do a search on low idle rpm assist for more discussions along the lines of https://www.v-strom.co.uk/smf/index.php?topic=43097.0 and https://www.v-strom.co.uk/smf/index.php?topic=39724.

The above does not explain the noise that you hear at 3,000 rpm.  Without a sound clip to hear the actual sound, I would try looking for something that may could be loose / rattle / buzzing / etc.