Mine failed with no smoke at all. The engine developed a loud squealing noise after it warmed up. Air was being sucked thru the front crankshaft seal which created the squealing noise, plus I tried to remove the oil filler cap while running, and could not get it off. Turn the engine off, relaxed the oil cap and cranked it back up, which then started smoking vigorously, but no squealing. 2 hour replacement job and about $135 for the AOS and J-tube.
