Small Engines (Lawn Mowers, etc.): Timing on a 12 horse, shear pin, cable ends

Question
My 12 horse tecumseh engine kinda groans when you try and start it,and acts like it is out of timing.We checked the shear pin it is ok.
Thanks Ray

Answer
Do you have an OHV or old L head engine?
Is the battery good?  Have you load tested the battery?
Did you remove and clean the battery termals and cable ends with a wire brush.  They may look clean, but clean them anyway...we get this problem a lot.

Will the starter turn the engine over with the spark plug removed?
Let me know.
Eric