I am having trouble figuring out the problem. It starts with out a problem when it is cold but after it is warm it has trouble starting. When I squeezed the fuel bulb it feels like there nothing in it but only after it has been running, when it sits for a fuel days the bulb is full & firm. I did find if I barely crack the throttle open it starts right up when it is warm. I thought it was the fuel pump and replaced it but that didn't fix the problem. Any help would be appreciated. Thanks!