[Al Skierkiewicz]

Sanddrag,
The carb has a sump tube that runs down into the gas tank and the tube has a screen filter at the bottom. If the gas had been sitting any length of time, the screen could be gummed up. As I remember the carb kit has a new screen as well. Since there is no fuel pump, the hissing sound is the carb trying to suck gas in from the tank, or bypass air around the choke or gas evaporating when it hits the hot engine parts in the intake. Since the engine runs if you squirt gas into the carb, suspect fuel delivery. You may find a manual online if you haven't looked already. B&G may group engines by family so the entire part number will not get a hit on their site. BTW, the choke (if not manual) is designed to open shortly after start. If it does not, try holding it open with a screwdriver while you start it the second time.