Small Engines (Lawn Mowers, etc.): Scotts lawn tractor Model #S1742, air hammer, silver spring md

Question
My son-in-law has a Scott's S1742. He was mowing the lawn and hit a stump with the mower, the tractor stopped and will not restart.

He lives in Silver Spring, MD and I live in Austin, Tx. I will be there later this week and would like to be able to assist him with the repair.

I appologize if this is a duplicate but I would not tell if the previous request actually was sent. Many thanks!  

Answer
Hi Lon,

I could almost guarantee that the flywheel key is sheared.  Although this usually only happens to a push mower, while tractors have some shock damping from the belts.
The flywheel is located under the recoil/cooling shroud. It is tapered and mates with the tapered crankshaft. The keyway in the flywheel and shaft keeps it from spinning on the shaft.  A nut secures it.  The recommended way to remove a flywheel is to use a puller.  An alternative, is to tap on the crankshaft top, with a brass hammer or use the round punch on an air hammer.   The flywheel will need to be held up and supported or upward pressure applied with 2 large prybars. (A 2 person job.) Care is needed so the flywheel doesn't crack or bend.  Also be careful to not mushroom over the crankshaft top.  Replace the key.  Install the flywheel after cleaning the tapers and re-tighten the nut to 65 ft/lbs.

Let me know how you make out.
Michael