I used to be a groundskeeper, and I operated a weedeater for the job. I had a gas-powered weedeater. I don't remember the make or model of the weedeater. When I turned power button to off to turn off the weedeater, the engine on my weedeater would sometimes keep on going for over a minute after I turned the weedeater off. Why did my weedeater engine keep on running after I turned the power to off?