I would like to get some more opinions on this phenomenon. Every now and again upon startup my engines will smoke and burn oil. This has happened to all my engines (kaw 14, kohler 14 & 15) at some point. It usually only happens once or twice a season, but still freaks me out when all that smoke comes billowing out for a minute. There seems to be no rhyme or reason to it. Is this caused by a speck of carbon or something getting under a valve seal and allowing a few drops of oil to drain into the cylinder?