Guys I asked for advice about my Craftsman Riding mower that was smoking about 6 weeks ago. One of you advised me to check the head gasket. I searched online and found a lot of other reports about this same problem in these engines. The problem has been getting worse over the last several weeks. I finally ordered a gasket set from B&S and tore it down today. You were correct, the head gasket was blown between the cylinder and the valve push rods. I replaced the gasket and put it back together. It only took me about an hour and a half to do he whole job and now its running like a champ again and not smoking. Thanks for your help!