I've been running the throttle down and letting my mower run a little at low rpm before shutting it down to avoid that "pop" when it's shutoff. I remember reading on here about it, a lot of people posted about it. Well, it only reduces the "pop". I was on the "throne" and the handiest thing to read was the owners manual for my engine! It said to shut down at full throttle! It works, no "pop" at all. Now, I started to run it down like before and then remembered what I read so I ran it back up and shut it down. Maybe that's why I didn't get any "pop".