Yeah, that's a classic sound—usually the clutch bearing. It's dry when cold.
The clutch drum rides on a needle bearing. If it doesn't have enough grease, or the grease has dried out, you get that metal-on-metal squeal on startup until friction warms it up. Here's the fix: you need to grease the clutch bearing.
- Remove the bar and chain (loosen the nuts on the side cover).
- Pull off the clutch drum (the sprocket the chain rides on). You might need a special tool to hold the clutch, but sometimes you can just pull it off.
- Inside the center of the drum, you'll see the bearing. Pack high-temperature bearing grease into the bearing cavity. Don't glob it on the outside.
- Reassemble. The squeal should be gone.
If that didn't work, the clutch springs might be weak or the clutch shoes could be worn, causing drag and noise. That's a parts replacement job.
Heads up: Do this regularly as part of maintenance, like when you sharpen the chain. A squealing bearing is a wearing bearing. If you ignore it, it'll fail completely and lock up.