Small Engines (Lawn Mowers, etc.): Trouble with lawn mower, 10w30, 10w40

Question
Hi, I own a Murray 20" 3.5hp lawn mower. I misplaced the papers that came with it and I don't know what kind of oil it uses. Without that information I purchased a lawn mower oil and filled it up anyway. After that I started the lawn mower up and white smoke kept coming out and later some oil came with it. Now when I pull on the cord to start it up it seems jammed and won't let me start it up. Could you please help me with some advise? Thank you for your time.  

Answer
I suspect you tipped the mower up without the spark plug facing up.  This will cause engine oil to fill the cylinder.  You will need to remove the spark plug, clean it and rotate the engine to discharge the excess oil from the cylinder out the spark plug hole.  Then make sure the oil level is correct, re-install the spark plug and it may smoke for a minute and clear up.  I recommend you use a high quality (synthetic is even better) 10W30 or 10W40 for oil.  Hope this helps.