I have a 5hp B&S with a pulsa-jet carb (fixed jet). If I take carb off the fuel tank and manually fill reserve bowl, engine runs just fine for roughly 2 min then quits (reserve bowl is empty). The fuel pump diaphragm is wet when disassembled and looks brand new. I was given the rototiller with the disclaimer that the previous owner narrowed down the trouble to the carb but had given up and I'm not sure what work or new parts he has into it. I have manually checked that pathways are clear and air flows freely. Spring looks good as well.

I've taken it a part, inspected, and reassembled about 5 times now.
Also, where do I get parts where they won't kill you on shipping?

Here's one of a thousand pages that illustrate the carb. (http://outdoorpowerinfo.com/repairs/briggs_pulsa-jet_horiz_fixed.asp)

Much Appreciated.

It's B&S P/N: 498298

I figured it out last night and didn't have a chance to reply. The copper tubing that extends from the carb to the fuel tank has an air leak thus not allowing the suction required. It looks like the copper tube is a "rolled" tube and it's leaking air along the seam.

My next questions is how do I replace it. This guy (http://outdoorpowerinfo.com/repairs/briggs_pulsa-jet_horiz_fixed.asp) says the part is machine pressed thus I'm thinking the whole carb needs to be replaced.

A) Is there a compound or bond that isn't gas soluble? Right now I used glue to test my theory and prove that it was an air leak in said tube.
B) The gas tank shows signs of rust on the inside. Should it be replaced no questions asked or is there options like running it until it shows problems or some sort of cleaner/solvent?"

You can pull out the tube carefully with vise grips and turning it. After that you can weld it with a propane torch ,flux,and a small wire of the same material... I had the same problem on an old edger motor on a minibike