Brand New Briggs & Stratton 725Exi won't start when hot

I just installed a new Brand New Briggs & Stratton 725Exi (purchased from Jack's) on a DR trimmer.  When cold, it starts perfectly and runs fine.  However, when hot, if it runs out of gas or stalls, the engine will not start and I have to wait until it cools down.  Once cool it starts and runs fine.  Any help is appreciated.