My son purchased a used Craftsman 917.374356 Platinum mower. It started fine when purchased. A week later, he was mowing with it and after 30 minutes, the engine suddenly stopped and would not restart. The oil was at the correct level and there was gas in the tank, The plug and air filter were recently changed. About every 10 pulls, the engine acts like it wants to start and kind of runs for about 3 seconds but never comes up to speed. It gives off a kind of wheezing sound when trying to start.