make sure to check the coil make sure youre getting spark to do that take out youre plug make sure you put coil wire on plug ground the plug pull recoil; if that's not it check to see if youre getting fuel
Clean out the carburetor with gas, the reason it wont keep running is its not getting enough gas through the carburetor.
check your coil out
Your flywheel key might be sheared
carb. adjustment, fuel filter or the engine is shot.
check to see if it is getting spark . you probably have the "kill mechanism " installed wrong . It's probably grounding out the ignition system. The "kill mechanism" is the cable operated mechanism that goes from the handle with a cable to the pull start housing . Its either improperly installed or out of adjustment.
Clean the carburetor with special attention to the high speed jet and fuel passage.
If its less than 20 horse power, it probably wont have one. Mine is a briggs and stratton 14.5 hp and it does not have one.
The solenoid may be bad. If you need help testing the starting system contact me through my board and I will try to help.
when it wont start
the engine wont start
Maybe Its The Muffler or the pistons hitting the engine
You may have overheated the engine or seized it.