I would say post a few detailed pictures of the engine bay so we can verify what has been removed and what has been replaced.
Remove the air cleaner for carburetor pictures and if you could post a short video of the engine running and making the sound you are concerned about this will also help with diagnosing the problem.
Remove the air cleaner for carburetor pictures and if you could post a short video of the engine running and making the sound you are concerned about this will also help with diagnosing the problem.