Have a 6HP Briggs & Stratton that keeps flooding out (gas) with cold start. Purchased mower (Toro w/self-propel) and worked fine for several cuts. Pulled plug, cleaned, and engine wants to start, will fire for 15 - 30 secs, then floods out....acts like a choke may be stuck??? Engine has primer plug. Any suggestions?

Sounds like you could have a carburetor problem. If your machine is new then don't mess with it. Take it to an authorized warranty repair center and let them fix it for you.