Small Engines (Lawn Mowers, etc.): Carburetor Problem

Question
Hi Eric, I have a push mower with a Briggs and Stratton engine model 122K02 0623 E1, code 061013FA. I removed the carburetor and disassembled it. I removed the seat by screwing a screw into the seat and pulling it out. I put in a new seat, ridge side down, and went around it with the blunt end of a drill bit. I also used a new needle that came with the seat. I cleaned the bottom jet with a straightened paper clip through the bottom holes and a small piece of wire from a wire brush through the top of the seat. I made sure to clean all holes in the carburetor and blow them out with compressed air before reassembly. I didn't remove any of the welch plugs. I reassembled it and bolted it back on the engine. I sprayed starting fluid into the carb to get it going. The problem is, it just goes dead after burning the starting fluid. I then tried another float to no avail. I just rebuilt a friend's carb just like this one, and did the same things and his runs perfect. I am at a loss as to what could be wrong. I even put the carb on another engine and it did the same thing. Could I have screwed the screw into the seat to far and damaged the carb to cause this? The bowl nut-jet gasket look pretty ragged but it doesn't leak gasoline. I saw a youtube video where the bowl gasket was to thick and wouldn't let the gasoline through the lower part of the jet. Could this be a possibility? If you could shed some light on what I need to do, I will sincerely appreciate it. Also, are those aftermarket replacement carburetors any good, in your opinion, that I see on amazon.com for $15 or $16? Thanks again for your time and expertise.  Stephen

Answer
Does it do the same thing if the gas tank carb is loosened?  Is the o-ring and intake tube loose or warped?

You stated you repaired a friends mower and it worked fine.  Can you borrow the know good carb and install on your engine to see if the know good carb works on your engine?

Eric