Small Engines (Lawn Mowers, etc.): mower wont start, head gasket, throttle plate

Question
Hi,
I'm going nuts trying to get a Craftsman 2 mower going. Its a 5.5hp self propelled. Ive taken the carb of and cleaned it, including soaking the pedestal with carb cleaner. (the emulsion tube has 2 holes in it , not just one big one in the center,I can blow thru it easily) the choke and throttle plates move freely. All springs seem to be good and in the right places (i bought a B&S Small engine care and repair book) Ive changed the spark plug and blade as I inherited it with no blade. I can however pour a tsp of fuel into the spark plug socket and the mower will run for 10-15 sec. Any suggestions ? (please!!) And I put on a 20 in blade, not sure what size it actually takes, does this affect the 'startability'? Iwould be most grateful for any help you could offer.
Thank you
John

Answer
If you have cleaned the carburetor is thoroughly as you say I don't think that is the problem.  One place would be to check the valves to be sure the intake valve is opening.  Also check the head gasket to be sure it isn't blown.  If none of these help go back to the fuel system clean the entire system including the tank and lines.  Remove the carburetor again and disassemble a special attention to the Main nozzle try to get it to screw out of the center of the carburetor.  Clean every air and fuel passages with a wire from a twist tab or similar.  Purchase a carburetor kit and new mounting gaskets install the kit reassemble the carburetor and mount using new mounting gaskets.  Attach the throttle and or choke cable and governor spring or link.  Put the throttle on the handle in the full position or wide-open position and be sure the throttle plate is standing open.  I think this will help your situation if not please get back to us.