I have a toro riding lawn mower, 16hp, briggs and stratton. It sat for about one month without being started. I went to strat it today and it would not stop smoking from the exhaust< white smoke. My oil levels were high and it seemed that gas had mad its way into the crankcase. I also noticed oil was comming out of the exhaust. Im thinking the rings need to be replaced but hoping its something easier to fix..... any sugestions .. thanks in advance