New engine in the BS 60-4s, 4-cycle ram-type tamper has 10 percent more power and is designed by Wacker Neuson to withstand rugged rammer applications, the company says. WM 100 engine allows the BS 60-4s to hit at 700 blows per minute and has an amplitude of 2.8 inches. Purge bulb carburetor allows operator to purge air out of the carburetor and replace it with fuel, which allows for easier, faster starting, the company says.