Small Engines (Lawn Mowers, etc.): Lawnmower will not turn, plug hole, spark plug

Question
I have a Sears  self propelled walk behind lanwmower, last year I hit an object. It now will not turn when I pull the crank.

I flipped it over and nothing is touching the base of the lawnmower.

The lawnmower cost me about $200 5 years ago, is it worth my while to have somebody look at it? Ideally I would like to fix it myself, but don't know where to start.

Sears has asked for $90.00 just to look at it, reimburinsg me for the difference if they can fix it.

Help...

Thanks

Chris

Answer
Remove the spark plug and see if the enigne will turn.  If it turns, place the mower with the spark plug hole facing up, then pull the string and watch the blade.

If it appears to wobble then most likely the crankshaft is bent.  If the crank is bent then I would replace the mower.

Let me know what you find.
Eric