This is a genuine Kawasaki FS481V-JS01-S 4-Cycle Vertical Engine, 1" x 3-5/32-inch (Replaces FS481V-DS01-S, FS481V-ES01-S and FS481V-HS01-S ). An absolute landscaping workhorse, the Kawasaki FS481V engine is a forced-air-cooled overhead V-valve 4-cycle engine capable of delivering compact power with surprisingly smooth operation and low emissions. Plus, this engine boasts Kawasaki Critical Power, SAE-Certified horsepower.