What is the push mower???
Perhaps the volume of the little filter cannister has something to do with it. Im thinking a vacuum lock.
It could be the head pressure. How high above the carb is the tank on the HM80?? As opposed to the mower??
You could maybe try a slight enlarging of the breather holes in the fuel cap.
On a different cap is probably a good idea.
Or rather than removing the filter/hose, plow some pressure in the tank before trying to restart.
Is the motor running lean?? Perhaps the fuel delivery when running is not good enough to keep the float level right.
Im sure its got a filter in the tank, perhaps filter the fuel before or when you are filling the tank.
