"With experience born on the raceways and roadways and a dedication to innovation, there's plenty of reasons to insist on the new Honda GX630 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 even gives their engines a 3-year limited warranty. Max. RPM 3,600, Shaft Keyway in. 1/4, Key size 6.3mm x 50mm, Throttle Control Manual, Mounting Base L x W in. 7 11/16 x 3 25/64 to 4 21/32, Cooling System Air cooled, Bolt Circle in. 5, 6 1/2, 7 3/4, Bore x Stroke in. 3.1 x 2.8, Torque ft./lbs. 35.2, Oil Capacity qt. 2, Shaft End Tapped Diameter in./Threads per inch 3/8-24, UNF2B, Air Cleaner Type Dual element/Cylindrical, Rated Power HP 20.3, Application Concrete saw, pressure washer, chipper/shredder, trencher, vibratory roller, ride-on cement trowel, Charging System Amps 20, Flywheel Brake No, Fuel Pump Boost type, EPA/CARB Approval California Air Resource Board Yes, Fuel Tank Not included, Cylinder Bore Integrated, Shaft Output Horizontal, Dimensions L x W x H in. 15 7/8 x 16 1/8 x 17 3/16, Compression Ratio 9.31, Low Oil Alert No, Ignition System Electonic, Digital CDI w/variable ignition timing, Crankshaft Q-type, PTO Height in. 5 1/4, Cylinders qty. 2, Carburetor 2-barrel, fuel cut solenoid, inner vent, Shaft Diameter in. 1, Lubrication System Full pressure, Fuel Type Gasoline, Engine Displacement cc 688, Engine Type GX series OHV V-Twin commercial-duty, Start Type Electric, shift type, Governor System Mechanical, Choke Control Manual, Shaft Length in. 2 29/32, Shaft Rotation From PTO Shaft Side Counterclockwise, Muffler Included Not included. Keyswitch 688cc air-cooled, 4-stroke OHV engine 50-state compliant engine"