Zenoah G300PUM (29.5cc) marine boat engine installed +1.0mm crankshaft in factory. It includes EZ starts and WT-1048 (13.5mm venturi) larrge bore carburetor. Specification and Technical Data: -Cylinder design with 4 transfer ports -High rpm piston with 1.0 mm single ring -New combustion chamber shape for 10 mm spark plug -Walbro WT-1048 large bore carburetor -Bore: 36.0 mm Stroke: 29.0 mm -Displacement: 29.5 cc (Engine Specification) Ignition: CDI-Type Magnetic Power: 3.7HP @13,000 RPM. Torque: 1.23 ft-lbs (1.68 N-m) @10,000 RPM. Timing: 30 degrees BTDC @ 8,000 RPM. Compression Ratio: 8.9:1.