I have a craftsman riding mower lt4000 while it was running the engine just stopped and now when I try to start it I get one clunk that's it I was not using it when it just stopped it was just started in my garage I was getting ready to finish plowing with it I used it for like 2 hours earlier and went back out to finish up started it and after about 3 minutes it just stopped with a clunk I checked the oil its fine it has fresh gas and suggestions it would be a tremendous help

Hi,
Clunks are rarely a good thing to hear. Suggest that you open the hood and physically try to turn the engine over in both directions. I could easily be wrong, and I hope I am, but "clunks" are most often thrown rods.
Peace,
Clarke

If you are lucky the cylinder is full of gas from the carb leaking through. If you can not turn the engine over by hand try removing the spark plug/s and try to turn it over again by hand. Let us know what happens.