Kohler k321 blowing smoke out around breather.

My Kohler k321 seems to be blowing smoke out from around breather. It's either blowing from the hole in breather or out around the rectangle plate gasket? What would cause this and how do I correct the problem? Thanks

Easy bit first, pull off the air filter and check the breather outlet is not blocked off .
Next pull the breather off and check that the valve is working by blowing and sucking on the outlet tube, yum .yum.

After that it is either a blown head gasket or a ring prolem.

The reason for blowing out the breather is excessive crankcase pressure. The K series Kohler is a flat or L head engine. A bad head gasket wouldn't give you crankcase pressure. Other then that I agree with bertsmobile yes if the air cleaner vent tube is plugged or crankcase valve bad can cause this or a ring problems.