Small Engines (Lawn Mowers, etc.): B&S Intek blowing oil, blown head gasket, craftsman lawn tractor

Question
I have a 2 year old Craftsman Lawn Tractor with a Intek 20hp Engine (# 31P977 0635 E1) and w days ago my wife was mowing and it started blowing smoke from the exhaust. It was due for an oil change but the oil was clean. the frame by the exhaust is covered with black oil and it continues to smoke. I believe it is a blown head gasket or valve seal. Any thoughts?
Thank You

Answer
Hello Doug, yes I do. Seals and gaskets almost serve the same purpose. However, it's an oxymoran. Gaskets are a material placed between 2 parts to prevent leakage. Seals on the other hand, are formed device made of plastic,rope, neoprene, viton. There use is to prevent oil leakage, around shafts etc.