Today I was mowing a yard like normal. I was mowing side to side on a really low grade ditch like normal and all of a sudden you could not find the front of the tractor from the white smoke. I killed engine as quick as I could let it set for bout 2 mins. Checked over motor everything looked fine. It smoke for about 10 secs after the start up and I had no more trouble from the mower. It mowed 2 more yards after that. The smoke got me worried that the motor was going to blow. The oil level was full, I check it every morning that I mow. The motor is just shy of 400 hrs. The white smoke was a thick cloud you could not see throw. The engine never made a funny noise or anything else. All help is appreciated.