If bought from a reputable, authorized dealer, the sale should have been reported to Ariens, along with the owner sending in or filling out some sort of registration. If bought elsewhere, with no paperwork, why would anyone expect any sort of warranty? Is there any indication other than serial number as to the model year and whether this machine has ever been put in service previously? It may be a 'customer return' or a 'buyers remorse' that was bought, registered and returned quickly.
If it was mine, I would be determining the existence of any sort of warranty, and if sold by a dealer, and lacking the factory coverage, as paltry as it may be, it would be on the trailer on the way back to the dealer. If the seller cannot provide and invoke a factory warranty, then there is something amiss going on that should be setteled as soon as possible. 'Time is of the essence" is held dear by lawyers and warranty vendors and they will not bend if you did not follow their explicit instructions, or were not given the chance to do so.