Briggs won't start

[pugaltitude]

You could really do with a spark tester to check for spark.
Has yours got a metal spark plug terminal?
They were prone for failing and allowing cold start but warmed up would cause no spark even after 30 seconds.
As long as carb is cleaned well, jet is cleaned in bowl nut, manifold is not cracked and fuel tank is good then i think your losing spark.
They are a brilliant engine and usually quite easy to repair.

 

[Fish]

Put the mower up where you can see things properly, like a tailgate. Remove the air filter and cover and look into the carb throat
and push the primer bulb several times. You should be able to see a pulse of fuel squirt up into the carb throat, if you don't
remove the base, and lightly cost that base gasket lightly with a smear of sealant on bot sides, but not too much, and reassemble, keep at it until you see it prime, you may have to replace the base, as that plastic warps, and it needs to seal good
as that is where the pulse goes to the carb to push the fuel up to prime....

 

[pugaltitude]

Noooooooooo dont put sealant on or anywhere near a carb.
Just fit more gaskets...

 

[Fish]

Nooooo. It works for me!!!!!!! Just have to take it easy on the goo!!!!!