Sorry I don't think YOU understand. A gas tank "should be vented". That means.... it should not pull a vacuum to the carb line. Which it no longer does as I rinsed the bronze filter ahead of the duck bill.
Why don’t you simply order the 2 fuel tank vent parts, then pull that assembly out to properly fix it?
It shouldn’t pull any vac in reverse like that, now you know it has failed & will leak gas out when turned on it’s side felling.
Why change something that works correctly?
With a tiny bit of normal vacuum the duck bill opens and lets air into the tank as it should, and in this case a little isopropal cleaned the bronze filter and let the duck bill function even better. I will change the pump diaphragm to the soft black version and ditch the blue mylar one.It won't pull much vacuum any more and I can watch the alcohol get sucked down in 3-4 seconds.
The saw has already started going back together and will be cutting wood late this afternoon.