Small Engines (Lawn Mowers, etc.): B&S 656CC Riding Lawn Mower (will not start), clutch pedal, step dad

Question
Marc,
  I am the proud owner of a 1984 Model 4-39003, 16 Twin, 4 speed, Electric Start, 16HP B&S Murray, 42" cut riding lawn mower.  Used...of course, and given to me recently by my step dad.  The problem is, that it will not start.  When he and I first loaded it up, it started and then ran out of gas.  I unloaded it at my house, filled it with gas and it would not start.  It will not even crank.  I thought the battery was bad, because the mower had been sitting outside...but replacing it left me with the same results.  The lights will not work, the mower will not start.  I am uncertain how to proceed.  I would appreciate any advice you might give.  

Respectfully,
Larry

Answer
My suspicion is that either a safety switch got damaged or the engine is hydraulically locked because of the the loading/unloading process but here's where to start.  Remove the spark plug and tie off the high tension lead away from the plug hole...now try cranking the engine over.  If it spews oil out of the cylinder, keep cranking the engine until it stops spewing oil.  Replace the spark plug, check the oil level and make sure the air filter isn't contaminated with oil.  Now start it.  It will smoke for a few seconds and clear up.  If this doesn't work, make sure the transmission is in neutral, the blades are disengaged and the clutch pedal is depressed.  Have someone hold the key in the start position and check for voltage at the starter terminal.  If you have power here and the engine doesn't crank over, the starter is bad.  If there is no power, the problem is related to either the battery, connections, solenoid or one of the safety switches.  Let me know what you find and I will try to help narrow down the problem, if necessary.  Hope this helps.