Small Engines (Lawn Mowers, etc.): Toro Recycler 20031 starting problem, personal pace, air hammer

Question
Michael,

I have a Toro 22" Recycler, 6.75 HP, personal pace, 20031 with electric start and I am having a problem starting the engine.  My son recently hit a rock which stopped the engine.  After that it ran for 20 minutes, but with a little more vibration.  I imagined that the blade was now out of balance.  After refilling with gas, the engine would try to start, but it would only turn over a couple of times before stopping.  It has recently been running well with minimal effort using the pull start (the electric gave out over a year ago).

I have read that hitting solid objects like this can cause a shearing pin/key to be damaged and cause these symptoms.  Could this be the problem?  Or should I be looking for something else?

Thanks for your help!

Joe

Answer
Hi Joe,

You are correct.  When the blade strikes an object, the flywheel key usually shears or deforms.  In that case, the ignition timing becomes advanced and the engine kicks back during starting.  I would remove the flywheel and take a look.  See my removal proceedure below.  Also, the vibration is something to be addressed.  Check the blade which may be bent.  Then look at the center of the blade shaft as it slowly rotates to see if that is bent.  It is easier to do this when the spark plug is removed and you have a helper pulling the engine over.

Let me know how you make out.
Michael

The flywheel is located under the recoil/cooling shroud. Its' bore 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.  Use an impact wrench on
the nut or a strap on the flywheel.  Don't put force on the cooling fins or they will break.  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 a punch
tip 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.