I have a 19 year old push type lawnmower with a Briggs and Stratton engine. It works well. It is a 3.5 hp model and does not have a float bowl. Instead it has a tube that sticks down to the bottom of the gas tank with a little strainer on the end. Ever since new it has taken 3-4 pulls of the rope to start it. That's fine with me.

This year I did not sharpen its blade so one day before cutting the yard I tilted the mower on its side so that I could easily feel the sharpness of the blade. It was sharp so I put the mower down and pulled the cord. It started on the first pull. Now I always tilt the mower on its side, gas tank up, and lower it and it always starts on the first pull. How nice but why does it do this? Is gravity causing the gasoline in the tube that is under the fuel surface to proceed into the intake and doing a priming job?

 

You got it. Try priming it more or less and you can achieve the same result.