What key? The old two cylinders just had a switch.My father and his life-long friend were in the part-time custom hay business, so I grew up in hay fields. I started out raking with an old John Deere 60. I don't remember how old I was, but when I wanted to stop I'd stand up, grab the clutch with both hands, and rare back with all I had. Most of the time that worked, and when it didn't I'd shut it down with the key.