There is an excess amount of oil being pushed out of the crankcase breather tube into the air filter housing. The compression is fine and there is no smoke out the exhaust. I am thinking a head gasket is the problem. Anyone have any experience with this problem?

crankcase breather tube into the air filter housing.

Don't know what that means. If you mean that the air horn has oil in it and oil is coming out of the breather, then I'd bee inclined to replace the breather assy in the crankcase. It's replaced from outside.

Something else you might check is the o-ring at the bottom of the oil fill tube.this was a common problem on this motor.