Just had a flat on my new Diesel Z and, for the life of me, I can't figure out what happened. I was mowing along and noticed that the right front tire wasn't touching the ground, so I stopped and looked at the left rear tire, it was flat. I grabbed the air tank, filled the tire and got the mower into the garage. It appears that the sidewall of the tire has multiple cuts in it. Looks like it was cut with a razor blade! This mower has less than 10 hours on it and has been kept locked in my garage since it was delivered in June. I haven't hit anything with the tire and I certainly haven't cut it with anything. My wife and I are the only people with access to the garage. I worked in the tire business for a few years back in the 80s, I have fixed and/or replaced hundreds of tires, I have seen many many flats that people drove on and cut the sidewall. The cuts on this tire are NOT from driving on it flat. There is no softening or abrasion of the sidewall which indicates having been driven at low or no pressure. The edges of the cuts are perfectly sharp edges and some are located on the sidewall in an area that the wheel could never contact, even if the tire was flat. This mower has never been driven off my yard since being delivered. I walked the entire area I mowed today, looking for something that could have cut the tire and found nothing. So, have there been any problems with defective tires on these mowers???