Ideas on carb replacement failure

[Rivets]

No, the cap is vent, that’s why it leaks.

 

[sgkent]

I don't think Mr. Rivets said anything about the fuel cap... ?

...you are applying pressure on the fuel in the tank,

so how would the fuel tank hold pressure unless the fuel cap was involved, right? Either the bulb sucks up fuel, or it pumps up the tank applying pressure to push the fuel up. Which is it? Why does the fuel bulb bleed down?

 

[Rivets]

The primer doesn’t hold fuel. Right now I can find my link to Briggs pulsa/prime carb operation. If you would google search “how does a Briggs pulsa/prime carb work” you will find videos on your carbs operating principles. I’ll keep looking.

 

[sgkent]

this is probably the one you refer to. I'll take a look at the diaphragm to make sure it is seating properly. Will also check the tank carefully.