Sounds bad but where is it smoking? Generally from underneath or from the engine area and installation? or elsewhere like from underneath? Sounds to me like you have run into something in the grass and bent something in the engine like the crankshaft. You hit something with these machines and the force is transferred inside the engine. Alternatively, and I know it sounds like a silly question but did you check the oil levels first? and now? Sorry to say but it is a trip to the nearest dealer unless you know how to pull one of these apart and put it back together again. The pictures you posted do not show anything obviously amiss, bent or broken so it sound like a serious engine problem to me. Sorry!