I may be getting older, but I refuse to grow up!
I agree, pull the side covers and check for a loose one way, flywheel, stator, clutch, etc.
You sir are a god, I'm glad you flipped - Just kidding.I'm new myself to raptors but wanted to chime in as I had a similar engine noise scare. A few months back I rolled mine being dumb and noticed almost the same noise (hard to tell from videos) after I started her back up, after about 45min of looking i noticed a bolt came out of my chassis skid plate and was vibrating on the frame, re taped hole new bolt no more noise. Hope its same issue for you man, whole lot cheaper and easier to fix.