Small Engines (Lawn Mowers, etc.): White smoke from exhaust then wont start, white smoke, burning oil

Question
I have a year old craftsman 6.75 hp push lawn mower. Today the lawn mower started to vent white smoke from the exhaust(about 15 min into the mowing) and then stopped running. Now the motor refuses to start up again and I am not sure what is wrong with it. I was wondering if it was something I did, I put 10-40W motor oil into it instead of 30W. I dont actually think this is the cause but I am not sure how this error is effecting the over all problem. Any ideas?  

Answer
Hi Dan,

White smoke usually indicates burning oil.  10W-40 is not recommended for summer use because it is too thin and that may be the cause.  Also check the oil level. If too high the excess may be burning off or if too low, engine damage may be occurring.  I would change the oil to 30 weight and try it again.

Let me know how you make out.
Michael