Has anyone had their mower tires filled with foam, in order to keep from having anymore problems with leaks or flats? The tire guy recommended only the front tires. He said the ride wouldn't be very good if I did the back tires. I have a ZTR, and a couple walk behinds. The newest Toro walk behind came with solid composite tires in the front. What's your experience been? I hate being shut down because of a flat tire.