Hi,
My friend's TTR has bad noise coming from cold engine only.
Please listen audio recording from 7s:
https://1drv.ms/u/s!Ar9YNbdz-p-shJpNFEbPR-5GBH0iBA
We suspect automatic tensioner.
The camshaft chain was changed last year.
When engine is wormed the noise is gone.
learning to ride on 1993 TTR 250
Ex 1997 and 1998 Honda XR 250
Sounds like you , were on the move for the recording .
id check the header pipe heat shield first that its tight and not bent close to the pipe .or loose going into the muffler
make sure all the engine mounts ect are tight
just to eliminate some of the basics first