The original post said the machine was running, and then quit. That means the kill switch and spark plugs are okay. It will run when starting fluid is sprayed into it, which points to fuel. Water in the fuel is possible, but unlikely since presumably the machine was driven home from wherever it was last filled. My guess is something electronic, and I would imagine the dealership as a first step connected the diagnostics computer. If you are lucky there is a failed sensor, which the diagnostic should have found. For your sake I hope it's not one of the machine computers. At least it failed at home.