"I use the mower for 1 season and the block blew out. I called John Deere and the warranty had just run out. They blamed me saying that I must have not put oil in the engine. Well the unit was supposed to have oil in it when I purchased it."
My car did too, but I check it on a regular basis. Thar oil doesn't last forever and must be refilled and replaced. I am sorry this happened to you, but it sounds like John Deere is not liable in this case.
And it is our responsibility to read the owner's manual for everything we purchase. I prefer it that way. Then I have all the information I need to use and maintain the hard earned purchase.