I have this 21 hp intek engine on a mower about 3 years old. It has been taken care of with easy life. Last fall it suddenly started smoking lots of white smoke. (I wasn't there when it first happened and don't know cause). Now gas shoots out the the breather when I give it gas above idle. Anyone know what it might be? Since it started doing this, I had my carb rebuilt but hasn't solved the problem.

Check your oil for fuel contamination. It sounds like your carburetor is flooding fuel and filling the crankcase with gas, thats about the only way fuel can come out of the breather tube, that I can think of.