"With experience born on the raceways and roadways and a dedication to innovation, there's plenty of reasons to insist on the new Honda GX660 V-Twin engine. There's superior engine design, with a 90 configuration that reduces vibration and allows a compact footprint. There's superior construction, with a forged steel crankshaft and an integrated cylinder head. Fewer parts means better durability. There's a digital CDI ignition coil that ensures improved fuel economy and lowered emissions. There's even improved air cleaning, meaning that you can wait 5 times longer between filter changes. Honda gives their engines a 3-year limited warranty. Shaft Length in. 3.11, Net Power Output HP 21.5 16.0 kW at 3,600 RPM, Bolt Circle in. 7 3/4, Governor System Mechanical, EPA/CARB Approval California Air Resource Board Yes, Start Type Electric, Compression Ratio 9.3 1, Cylinders qty. 2, Bore x Stroke in. 3.1 x 2.8, Engine Type Air cooled, Carburetor 2-barrel, fuel cut solenoid, inner vent, Net Torque lbs./ft. 35.6 48.3 Nm at 2,500 RPM, Shaft Rotation From PTO Shaft Side Counterclockwise, Shaft Diameter in. 1, Oil Capacity qt. 2.3, Ignition System Digital CDI, Engine Displacement cc 688, Lubrication System Full pressure, Air Cleaner Type Dual element. Full pressure lubrication system Forged steel connecting rod Mechanical governor system 50-state compliant engine"