Small Engines (Lawn Mowers, etc.): Engine quit, oil tank, fuel flow

Question
I have an identical dilema to the person who wrote "Is my engine dead?"
Craftsman walk-behind.  Model? 3 years old.
Drained the oil after last season, may have underfilled this year.  It had been acting sluggish so far this year, made it thru one cut.  Then 20 minutes into its second cut, started idling faster and faster until it quit.  
Some smoke came from the oil tank.  But the flywheel WILL turn over when I crank.
What could I check first?

Answer
Hi Aaron,

How was the oil level when it quit.  Okay or low and how low?  If it is okay and you don't think it was seized and just won't start, then follow my proceedure below:

Let me know how you make out.
Michael

You will need to determine if the problem is a lack of spark or a lack of fuel flow.  Right after it quits, remove the spark plug, reconnect the wire and lay it against the engine head.  Pull the engine over and watch for spark at the plug's electrode.

If good, then try to start it while squirting fuel or starting fluid into the carb intake.  If it starts and you can keep it running by adding fuel, then the carb most likely has dirt, debris or gummed fuel inside.
First, check the gas cap to make sure it is venting and not causing a vacuum in the tank.  If that's okay, you will need to remove the carb, disassemble it, clean all the small internal openings and blow it out with compressed air.   Probe each and every hole with a small wire.   A carb rebuild kit wouldn't hurt either.