After starting my Craftsman generator, it will run for (exactly) 60 seconds then just dies, it does not sputter like it is running out of gas, it just shuts off. After a few minutes, I'll restart it, and it'll run for 10 seconds and dies again, this will repeat until I quit trying to start it. I have pulled the gas line, thinking it was a clogged line; it's not, I cleaned the bowl, tried carb cleaner, it still does the same thing. What is the cause of this?