Small Engines (Lawn Mowers, etc.): 12 hp mastercraft riding mower, jumper cables, booster cables

Question
My wife caught some sting today and stopped the mower and shut it off. She pulled out the string and when she went to start it to carry on cutting it would not start. I checked all the safety switches, they are ok. Battery is at 12.7V, it does not even try  to crank over. It is a12 hp, model # OHV125. 2030388 Tecumseh engine. I went direct from the battery positive to the starter with booster cables and it did not turn over. Just wondering what I should try now.
Thanks
Steve

Answer
Bad battery?  If the starter will not turn by connecting it directly to the battery then either the starter could be bad or the battery could be bad.

Are you sure the cable connections were good when you used the jumper cables.  I would recommend removing the spark plug BEFORE trying to use jumper cables directly to the starter...less current and less sparks.

Are the starter teeth binding on the flywheel causing the starter to jam and not turn the engine?

Eric