Is this in the water or out or in neutral? Check the vacuum control wires and hoses on the starboard of the motor — it’s a device situated between the fuel pump and the shift linkage. When there is excessive vacuum, i.e. runaway , it momentarily interrupts the ignition. Look for punctured diaphragm, leaking hose, loose/frayed wires.
The pic isn’t so great — it’s from a basket case in my garage.
