I have a 223 with a Kolher pro command engine. At times, when it is given full throttle it tries to die off. I can let off the throttle handles and it will perk back up. Seems to be worse when engine is warm. It always starts right back up no problems may go another 30 minutes then does it again or it may do it several times in a row. Really bad if trying to mow grade because of need to push more throttle. We have changed fuel filter, cleaned trash from bowl, tested coils, stator, changed air filter, and added sea foam to the fuel. I have been able to mow and have added new fuel as it gets low. Very frustrating! Help please!
I had a very similar issue. I did everything you did plus traced wires. One night I happened to see the governor spring was not attached towards the front of the motor. It is very thin and broke the end off. I ordered a new one and mowed 4 acres with no issues.
To test for a coil dropping out when hot. get a pair of red / orange in line spark testers.
These can be fitted to the engine before you start mowing so when it stats to play up it is simply a matter of looking at them
They should both be glowing at the same colour
In fact they are flashing but at idle speed they flash too fast to be seen as flashes .
The other option is a fuel supply problem cause by a vacuum lock in the fuel tank or floating debris blocking off the fuel out let.
So try loosening the fuel cap 1/2 turn .
If that makes no differece you can try blowing back through the fuel line from the tank side of the fuel pump or using a make shift alternative tank ( pinch it off your push mower , old motorcycle etc )
Debris and in particular grass clippings remain in the fuel tank and like hair nthe shower, eventually block off the outlet then flaot away when the engine is not sucking fuel.
Governor issue, linkage, spring, etc. Or maybe carburetor accelerator pump partly clogged. Acetylene tip cleaning file sometimes can be used to ream out that passage. Other times may need overnight soak in carb cleaner.
