Small Engines (Lawn Mowers, etc.): JD L-110 Wont start, carburetor, jd

Question
My JD won't start and I have tried everything i can think of.  I cranked the carburetor and took it to a local mechanic and he said it was fine.  I crank and crank the engine and nothing but backfire.  i changed the coil and plug and checked the spark and still nothing.  Please help since I have no way of taking it to a mechanic

Answer
How old is the mower?  If you spray starting fluid directly into the carb will the engine try to start?

Did the problem happen suddenly or has the mower sat a while?  Is the fuel less than 30 days old?  

Let me know if the engine will start with starting fluid.
Eric