I have a Ariens riding mower with a V-2 656 cc 20 HP twintek engine and this morning I discovered that my crankcase was full of gasoline when I checked the oil. The oil level was way too high and I thought that I may have been sloppy putting oil in the engine. But then I realized that the oil was as fluid as water and it smelled like gas. i did not notice any problems 3 weeks ago when I used the mower last. How did that much gas get into the crankcase and the engine still running great the last time I used it

Either a vacuum operated fuel pump leaking or the carb needle leaking fuel and not sealing... 
 
If you can loosen and pull the carb away (fuel line still hooked up and turned on) you can check for leakage/fuel coming out of the carb into the intake manifold.
 
 
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Yes you might be on to something here with the needle. I will remove the carb today and check it out. Keep you posted! Thanks

SRT you nailed it. Thank you so much. The problem was in the float bowl. There is a part in there that is sealed with an 0-ring and that 0-ring was broken

Excellent, glad you found it...!