Small Engines (Lawn Mowers, etc.): B&S 6.5HP Engine, compression check, float bowl

Question
I have a Sears push lawnmower model (917-388751) with a B&S 6.5Hp engine, model (BSP-123K02-0181) that will not start. I did remove the carburetor and it was very clean. I blew all the passage ways out and re-installed it with new gaskets. I can prime it using the primer bulb 3 times or 50 times (doesn’t matter) and it will crank on the first pull and then it shuts back down like its not getting gas.  I can remove the spark plug and put a small amount of gas into the cylinder and put the spark plug back and it will crank with the first pull. It will only run for a couple of seconds and shut back down. I removed the head and there is no cylinder wear at all and the valves look good. Before I removed the head, I did a compression check and it was reading 70 psi. This mower is a couple of years old and hasn’t been run very much. Thanks for your help.

Thank You,
R.C.
rc5034@spydee.net  

Answer
Since the mower will start when primed, then the compression, timing and ignition are fine.  The problem has to be with fuel delivery.

The float bowl nut should have a hole in the center.  Is this hole clean?  Is the fuel fresh?  Sometimes the carburetors need to be cleaned a couple of times to get them working.
Re-clean the carb and let me know what happens.
Eric