I have a Big Blue 300 and a few days ago it started shutting down on its own, yesterday it ran most of the day and then shut down on restart it would run less than a minute and shut down, its not hot, oil is good, fuel is good it does have a slight leak t the injector pump but its ran 10 hours a day since june like that, today did it twice and then ran until lunch/started and ran the rest of the day, any ideas, I'm thinking bad shut off solenoid but?

PS Im new here, hello everyone