When I was a kid, I remember my dad buying a Sears & Roebuck self-propelled walk behind. It had a Briggs 5hp motor, gearcase that drove a chain to the shaft the had two rollers pressing on the front wheels to make it go. You could lift the shaft to push the mower if you wanted. It was all metal, and heavy as hell. Oh, and my dad made me mow all seven (yes, that is 7), acres of yard on our farm in Belcross, North Carolina 27918 from 1966 until 1974 when he bought a riding mower for my younger brothers to use. I wore that damned heavy-assed mower out. In the heat. In the humidity. Did I mention we lived on the edge of The Great Dismal Swamp? In North Carolina? In the summer?