When blades are disengaged, engine drive pulley still spinning.
I have a Murray 42” deck riding mower. After mowing for an hour or so the mower started smelling of burned rubber. I turned it off and left it for a few days. Upon starting again it immediately smelled of burning. Blades disengaged obviously for startup. The engine drive pulley (the one nearest the front of the mower holding the deck belt) is spinning and just shredding the drive belt to smithereens. It’s not supposed to spin when the blades aren’t engaged, right?? Why would it be stuck like this?
ETA: photos of the mower, a 14hp 42”deck. The model number sticker is entirely worn off so no idea. Best guess after hours of online searching is a 2004.