I have a Troy Bilt riding mower with a Briggs and Stratton 17.5 HP motor Model#31C707-3346, it has been sitting for 2 years and was given to me I am trying to get it running so I...

1. Replaced Air Filter
2. Drained old fuel
3. cleaned Carburetor
4. replaced Spark plug
5. changed oil

And for some reason it still will not start. Any suggestions on what might be wrong? It turns over but will not run

Have you getting spark at the grounded plug? Gas at the carb? Make sure the needle is free of the seat, I've seen them stuck together from old gas. Fuel line open?