2004 Riding Mower Turns Over Won't Start?

It's my project this summer now! I bought a used 2004 riding mower last year and it worked ok. The end of the season last year it started to need to be jumped via my car. I charged the battery from last year, got the engine to start once but it stalled and then nothing. I bought a new battery this year but it still didn't start to crank over. All I got was a clicking sound when I turned the key. I then "jumped" the solenoid (from reading ideas online) and it began to want to crank over. But no actual running. I replaced the solenoid and the key now engages the motor but still no starting. I bought and replaced the fuel filter and let some of the gas run through the tube to the ground to flush out anything that may have been in the tube. I also changed out the spark plug just in case as I continue to troubleshoot this darn thing! That's where I'm at. The engine still cranks and cranks and cranks but never any actual running. Ideas please!