Ultimately depends on the surge. Unless there is an actual missing chunk of the drive belt it is actually unlikely to be that. Now I am going to assume it is an auto drive model, These have a friction clutch drive system, first place I would start. Also they have a chain drive, that could be worn out or loose also.
Yes these have 3 drive belts. there is a belt from the engine to the clutch assembly, then there is a belt on the clutch assembly itself. Just have a look at them, Could just be loose also.