Troy Bilt TB280 ES wont start with out help

I can not get the mower to start without having to hand throttle the link on the carburetor itself. This model does not have a throttle control on it. It's supposed to be grab the bar, push the button and it starts. I can not figure out how it knows to give itself gas to start. I got the choke figured out. Once I hand throttle it, it runs fine. Just takes 2 people to start it. Any suggestions?