Small Engines (Lawn Mowers, etc.): Tecumseh mower starts then stops, ohv engine, spark plug

Question
2000 Scotts self probelled Mower with a 6.5hp tecumseh motor.
OHV; engine mdl ovrm120; engine family ytpxs;
mdl 22965x8a

Mower would not start. I sanded the magneto due to rust; replaced the spark plug; replaced the carburetor gasket, needle and seating.  The float appeared to move freely.  Placed fresh gas into take after reassembly.  Engine starts then stops.  What did I miss?  Help?

Answer
Hello,

The carb most likely has dirt, debris or gummed fuel inside.  You will need to remove the carb, disassemble it, clean all the small internal openings and blow it out with compressed air.  Probe each and every hole with a small wire.  A carb rebuild kit wouldn't hurt either.  

Let me know how you make out.
Michael