I have a 20hp Kohler on my Tiger cub and it has been smoking on and off (blue smoke) at startup since it had about 50 hrs on it. The dealer did a leak down test and said everything is fine and even the Kohler rep doesn't seem to concerned. The mower has almost 600hrs now and it still does this although it doesn't seem to use any oil. Just thought I would ask if any of you have exprienced this and what you know about it. I will add that I change the oil often and that I use Mobil1 10/30. Thanks.