I have a decently nice Snapper push lawn mower with a Briggs and Stratton engine. I have it tuned up every year (it's only two years old). I have the height setting about 2nd or 3rd tallest grass setting - I try to keep it high. However, when I went over some grass yesterday, it must've been more than it wanted to handle (grass had been sprinkled earlier that morning, but this was at 7:00 pm so it wasn't very wet at all). It stopped. I turned it over to the correct side so oil wouldn't leak. I cleared out any loose grass and turned it back over. It wouldn't start. I waited an hour and tried again. Tried again today. Still not starting. It will huff and puff a couple times, but isn't that close to rolling over. Occasionally when I pull it it will make a loud clunk noise and stop. Another couple of times, it almost sort of felt like the blade seemed to go in reverse for a rotation or two. Very strange. If I take it in, it will probably take a couple months to get back. I would love to hear any feedback on what might be causing this so I could steer clear of taking it in! It's got all the proper fluids. It's a self-propelled mower, but that part looks to be working fine. Any feedback is appreciated!