Small Engines (Lawn Mowers, etc.): Kohler Courage engine problem., husqvarna lawn tractor, flywheel

Question
Hi. My neighbor and I were discussing his Husqvarna lawn tractor with Kohler Courage engine. It broke down last year and he took it to a shop who said it was a seal/bearing on the crankshaft that failed. Wasn't cost effective so he brought it home. Well we were talking about it and he said he was mowing when it started making a high-pitched squealing noise and shut it down. It would not crank after. A friend of his mentioned that there might be a bolt or screw under the flywheel that can back out and scrape against the underside. Which would explain the noise and the inability to not be able to crank. Could this be the issue?

Answer
It could be an external part.  If the engine will not crank I would start by removing the spark plug and checking to see if it will crank with the plug removed.

Next, make sure nothing on the bottom of the engine is binding, mainly the belts.  If there are no belts binding or froze then start removing external engine parts and re-checking if it will crank as you remove parts.  If you get down to the flywheel and the engine will still not rotate then something inside is the problem.  

Take lots of pictures as you dis-assemble in case you do find something came loose and you can fix the engine.

Eric