En for some commercial applications. With a 37.7cc 4-stroke engine putting out 1.5 horsepower, this blower offers excellent power in an ergonomic. You can feel a strong wind moving between your back and the blower body. The 4-stroke backpack blower has a much more mellow tone.It differs greatly from the high-RPM screaming 2-strokes. Super light weight 17.5lbs. Allowing you to move around freely. Engine displacement (cm³) 37.7. Dry Weight (lbs) 17.5. Fuel tank capacity (l) 0.67.