Small Engines (Lawn Mowers, etc.): Craftsman Siton Lawnmower, craftsman model, plug hole

Question
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Followup To
Question -
My mower will not start.Its a Tecumseh,4 stroke 12 HP overhead values,electronic Ignition.With the spark plug out, it turns over normal,With the spark plug in,it turns over once but slow.The year 1986,Craftsman,Model#944.605120. No repairs done to the Engine.the Spark plug is new, the battery is new.Bty cables &bty post cleaned.I have spark and good compression.the bty has had a load test.

Answer
Has the mower sat for a while?

If so then there may be some oil in the cylinder causing the piston to hadralicly lock not allowing the starter to turn the engine.

Remove the spark plug and crank the enigne with the spark plug removed...does any oil or oil vapor come out of the spark plug hole when you crank the engine?

Let me know what happens.
Eric