John Deere Riding Mower Won't Start?

I have a JD 18 HP. V twin; it's a Kawasaki engine. It has spark at the spark plugs and it's getting gas into the carb and to the spark plugs. It will crank over, but will not start and run. I drained the gas and put new gas in it and it still will not run, just will crank over. The battery and all are in great condition. What can I do next?Please I need help ASAP.

I can't take it to the dealer cause of what they charge to fix stuff. It's a 2005 or 2006 model. Here are some of the numbers I took off it, FH580VBS04-R, FH580VA94857, and KAXS.686N40B. It has been sitting unused for about 4 or 5 years, but like I said I have changed everything and cleaned out everything also. It just won't run!

By Tami M.