I worked on my lawnmower. First I replaced the filter and was looking into the primer bulb being bad possibly, the mower started and ran after 2-4 pumps but cut right out. I was looking for direction online on how to replace the bulb and found a video of my exact problem. It was such an easy fix I was able to do it. One of the holes in the nut at the bottom of the carburetor was plugged up.
I could not find my vise grips so used a chips bag clip to pinch off fuel line.
I will share link here. https://www.youtube.com/watch?v=Gy–7hcBFps