Arm yourself with a can of carb cleaner and one of these spark testers
https://www.amazon.com/gp/product/B0000AXCOV/ref=pe_1275710_280022250_em_1p_3_ti.
Install the spark tester pop the can of carb spray in the drink holder then go mow.
When the mower stops flip the hood , crank the engine and look for a red flash in the spark tester.
If it is flashing as the engine cranks then whip off the air filter and give the carb a shot of carb cleaner then crank again.
Engine fires then Blaz was most likely correct.
If there was no flashes from the spark tester, pull the blower housing off and remove the kill wire from the coil.
replace the blower housing then go mow again, taking extra care because you are now relying on the carb solenoid to stop the mower.
If the engine stops again and there are no flashes from the tester then the magneto is toast.
If it stays running then you have a problem in the wiring, do not use the mower like this, it should only be done as a test.
IF the engine fired right up with the carb cleaner, then the problem is in the fuel system some where, get back & we will go through how to check the system from tank to manifold.
If you have a spare tank of some sort kicking around ( a quart one off a push mower will do ) you can try plugging it into the fuel pump just after the mower stops which will confirm the blockage is in your tank.
