I have a push mower with a Briggs and Stratton 300E engine. When you try to start it will fire up once for about two seconds and then die. I took the carb off, took it apart, cleaned the jets with carb cleaner, sprayed out the bowl, put the needle back on the bottom of the float, put it all back together, filled it with new gas and got nothing. I then took out the spark plug and cleaned it really well with carb cleaner and put it back on, still nothing. I drained the oil and replaced it with new. Nothing. One thing I have been noticing is that when I press the primer button, I get nothing, it just sounds like air. Where should I go next?