That's a possibility or a clutch bearing, but you would think it would change with the clutch engaged since it would then all be turning together.

I'm starting to think it could be the 1-way bearing for the starter shaft dragging or a crankshaft bearing. See if you can turn the engine over by turning the flywheel and hold the starter shaft still.

Just make sure you don't turn the engine over backwards or you could break the pull start.