Honda CB 750 Custom Rattling Engine Noise

[big8mistake]

Hello

I have a restored Honda CB 750 Custom from 1981.
The motorcycle has undergone a major renovation. Chains with tensioners, pistone rings, valve seals, pans and bushings have been replaced in the engine. The problem is that when I start the motorcycle on the choke, even on warm days, for the first few minutes I hear a characteristic sound. When the motorcycle warms up, it disappears. Yesterday I did the camshaft chain adjustment and it didn't help. I guess it may be the fault of the carburetors, they were not completely regenerated. Let me know what you think. Below is the a link to the video:

https://www.youtube.com/watch?v=OjcbyaelkwU&ab_channel=KatarzynaParzentna

 

[Pwnypower]

Does the sound go away with the clutch pressed in? Maybe it can also be the chain that connects the crank with the gearbox.
It makes a rattly kind of sound on my CB

 

[fg1972]

Sounds a bit like either the timing or engine/cam chain. Assuming on the front of the engine you've loosened loosen locknut and back off the bolt while engine is running then retighten to adjust the tension on the timing chain but have you done the adjustment for the other chain? Loosen the 2 x acorn nuts behind the head then retighten while engine is idling? Other than that, she sounds very nice.