Briggs & Stratton 21 HP Intek® Vertical OHV Engine with Electric Start delivers top performance to meet the demands of professionals. The OHV engine features a pressure lubrication system with an automotive full-flow style spin-on oil filter that cleans contaminants from the oil. U.S.A. Displacement (cc): 540, Shaft Dimensions Diameter x L (in.): 1 x 3 5/32, Application: Riding lawn mowers and lawn tractors, Shaft Output: Vertical, Engine Type: OHV, Start Type: Electric, Mounting Base L x W (in.): 10, Shaft Keyway (in.): 1/4, Shaft End Tapped (in.): 7/16-20, Max. RPM: 3,300, Charging System Amps: 9, Ignition System: Magnetron® Electronic, Cylinders (qty.): 1, Oil Capacity (qt.): 3, Air Cleaner Type: Dual element includes automotive-type pleated paper air filter and foam pre-cleaner, Muffler Included: Yes, Low Oil Alert: No, Lubrication System: Full Pressure, Shaft Rotation (From PTO Shaft Side): CCW, Bore x Stroke (in.): 3.70 x 3.06, Cylinder Bore: Cast iron, Cooling System: Air Cooled, Carburetor: Float, Fuel Pump: Yes, Governor System: Mechanical, Dimensions L x W x H (in.): 19 x 16.5 x 13, EPA/CARB Approval (California Air Resource Board): Yes AVS™ Antivibration system Enhances gear-driven lubrication system by delivering oil directly to the lower PTO bearing to safeguard against wear Large-capacity air filter traps more dirt and debris