I also have a 3 year old john deere la125 with 160 hrs. have used it 6 times already this season and it has gradually been producing more and more white smoke mostly under load with the blade engaged. It is starting to use oil which I know is not good news. This la125 replaced another john deere twin cylinder I had and the carburetor went bad while under warranty. Can you tell me what is happening with the white smoke issue.

White smoke oil.
Black smoke fuel.
Check your oil level and see if its over full,
If so make sure there isn't gas getting into the oil.