Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Twin engine. So coils would not both be quitting. In the carburetr is an electric solenoid, it can kill engine if it does not stay retracted. It plugs the main jet in the carburetor and has to open with12 volts, as soon as the key is turned on and has to stay openas long as the key is on.
It may be getting hot and collapsing, then when key is cycled, it resets , but each time it starts will run shorter period of time. Best test is to remove it and run test with it out.
Alos , does your engine have low oil pressure. high temperature shutdown? If so, can be oil pressure or temperature switch.
I have not heard back, did you find problem?