Small Engines (Lawn Mowers, etc.): Oil sprays out of filler tube, hard to start, kickbacks sometimes, air hammer, filler tube

Question
Hi,
I was given a non-working Craftsman 6 HP mower, with no history.  When trying to start it, it would periodically kickback the pull cord.  I finally got it to start, and noticed oil leaking out from the bottom of the oil filler tube (where this plastic tube meets the lower part of the engine).  When I opened the oil filler cover, it sprayed oil and the oil might have been warm.  I believe that this is a Tecumseh engine/carburetor.
Thanks.

Answer
Hi Ken,

Sorry for my delay.  The holiday was busy here.

I could almost guarantee that the flywheel key is sheared.  The timing would then be off.  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.
There is also the possibility of a bent or twisted crankshaft depending on the severity of the impact but usually the key just shears.  

The oil problem may be due to a clogged or defective breather tube or pcv valve.  This is located on the side of the block.

Good Luck.
Michael