Small Engines (Lawn Mowers, etc.): engine problems, plug hole, crankshaft

Question
My friend has a mower that he ran into a tree branch with. The engine is really hard to turn. It is a B & S engine. It is an older engine. I dont no why it is so hard to turn. Can any one help?

Answer
 Hello David:

 Remove the Spark Plug. Tilt the Mower so the Spark Plug Hole is Facing Up. Check for a Bent Blade. Turn the Engine by Hand and Watch the Blade Bolt(bolt that Holds the Blade onto the Crankshaft). Does it Wobble? If Yes, then the Crankshaft is Bent. Depending on How Bad the Crankshaft is Bent it can Cause the Engine to be Hard to Turn. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. I enjoy knowing the Outcome. Thanks.

 Good Luck

 Respectfully

 John