I have a Troy Bilt push mower that will not start. Gas is good. Spark is good. When pulling on the rope, I'll get it to pop a little, but that's it. :)

Is the choke closing?
How is the air cleaner?
Can you start it without the air cleaner installed?

Sounds like a flywheel key to me. Check that.

I think the mowermans right sounds like the flywheel key