Briggs and Stratton 3.5 push mower. rebuilt the carb and runs great but after 15 minutes the primer bulb sucks in and it starves out of fuel
You may experience this problem because your ignition coil is failing when it gets hot. Make sure the cooling fins on the flywheel are not plugged up. You will probably have to replace the coil.
How old is your lawn mower?!
Wrong diaphram in carb, or missing check valve(ball) following primer bulb inside carb housing