Small Engines (Lawn Mowers, etc.): case 448 stalling, case 448, condensor

Question
I have an old 448 Case, Onan engine.  It has started to stall after running about 20 min.  I can get it restarted, although hard.  Then it will move about 3 to 4 feet and stall again.  The gas line has been replaced, gas tank cleaned and emptied.  Carb cleaned, the shop that did the carb cleaning said they ran it for an hour and it didn't quit.  However, when I got it back it ran for about 20 min, was going up a hill and it stalled.  Have not been able to mow with it since.  The shop that did the work said they didn't know what was wrong.  Any suggestions?

Answer
 Hello Phyllis:

 Has anyone Checked the Ignition Module or Point Set. When the Ignition Module or Condensor (if Point Set) get Hot they will Ground Out. If the Shop didnt put the Mower Under a Load; ie Cutting Grass; they will not get the Components Hot enough to Ground out. Use the Mower and Check the Fire to the Plug when it Stalls the Next time. If no fire then Replace the Ignition Module/Point Set. Also the Valves will cause this type of problem when They need to be ReGround and Lash Reset. Hope this Helps.

 Good Luck

 Respectfully

 John