I have a Vitpilen 701 and around 5-6000 rpm, stuff on the bike buzzes, rattles or vibrates. I don’t think it’s the engine because I’ve started to strip plastic parts and the cat covers to prove or eliminate them as the source of the buzz. Removing the black cat covers took out some buzz, as well as the plastic radiator end caps. But I still have something buzzing or vibrating like a plastic sound. It’s really bugging me, as I want a super tight engine only growl to the bike.
A single vibrates a lot, that just is what it is. Beyond that, I haven’t noticed anything rattling on mine, though I removed the cat ages ago.
Fun fact, the single vibrates so much it broke the optical stabilizer in my iPhone mounted to bars… twice. I’ve never had that issue before in phones mounted to 3 different bikes. I added some compression foam to the mount since the second incident, hoping that solves it.
So it turns out that I finally found the major source of the buzzy noise. It was the stock mirrors! The plastic housing buzzed against the glass mirrors. So I put bar end mirrors on and it sounds like a growly bike now.