Small Engines (Lawn Mowers, etc.): briggs shortblock, starter fluid, carburator

Question
hi i just finished rebuilding a short block for a Briggs 28t707-1154-ei code is 010531 zd the short is part number 496606 this 12.5 hp. well anyway after i was done it ran and started fine but when it warm up it stop running. now I've been doing repair work for four years the top half sounds a little loud like valve noise. The other block had a broke connecting rod they sad it had to much oil in it and it was coming out the breather hose that connect to the air cleaner housing. They the owner said he had drained some out. so now the problem with the new block when it stops after it warms up i think it could be the breather assembly it is the one off the old block but you are the expert so any answer would welcome thank you for your time have a nice day

Answer
 Hello Mike:

 The Breather Assembly you are Talking about is the Crankcase Vent. If the Engine Isnt Smoking the Vent is Working. If the Isnt Working then Oil is Pulled from the Crankcase and the Engine will Burn  the Oil and Smoke. If you Shake the Crankcase Vent it should Rattle if it is Good. 1- Check for Fire at the Plug when the Engine Quits. If No Fire at the Plug, then the Coil/Ignition Module is Bad. 2- Check the Gas Tank Cap and Ensure it is Venting the Tank Properly. 3- Trash/Water May be in the Carburator. When the Engine Quits and you have Fire, Try to Run the Engine with Starter Fluid. If the Engine will Start with the Starter Fluid, the Carburator is the Problem. If the Engine Does Not Run on Starter Fluid when it Quits and you are Getting Fire and Gas, then Check the Compression. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John