Small Engines (Lawn Mowers, etc.): lawn mower repair, starter cord, tecumseh engine

Question
Michael,    I was given a non-working MTD self-propelled lawnmower with a 5.5 HP Tecumseh engine.  Model 124-477DO13.  It kicks when I try to start it.  I pulled the flywheel and the flywheel key appears to be ok.  I pulled the blade but it doesn t have a blade key.  The end of the crankshaft is a ridged affair and the blade has a cup fitting with equivalent ridges that the two pieces slide together.  I didn t see a problem there.  While I had the blade and blade assembly off I attached my half inch drill with a socket to the nut on the flywheel so I could spin the crankshaft fairly fast and do so continuously.  There might be a very very slight hint of a wobble in the crankshaft but hardly detectable.  It clearly (in my non-expert opinion) is not badly bent, if bent at all.    The crankshaft rotates smoothly and easily with the spark plug out. When I pull the starter cord with the spark plug in, the engine sometimes will not rotate at all.  I can lift the front of the mower off the ground by pulling on the starter cord.  It s like something wrong inside the engine.  What else would cause this thing to be out of time so it kicks like that.  Connecting rod?

Answer
Hi Frank,

If it kicks back, trying to pull the cord out of you hand, then the timing would be off.  Since the flywheel key is intact, the crankshaft may have been twisted, even though it isn't bent.  Probably due to an impact with an object. If it just won't pull over, then there may be a valve malfunction, as you suspect.  You might check for compression, either with a tester or a rough test by using your finger to feel for vacuum and pressure at the spark plug hole.

Let me know how you make out.
Michael