Abstract: An internal combustion engine comprising an engine block, a crankshaft rotatably supported by the block and including an axis, a first portion which is cylindrical in shape, which is concentric with the axis, and which has a uniform radius, and a second portion extending from the first portion in concentric relation thereto and having a radius less than the radius of the first portion to define a radially extending shoulder on the first portion, a flywheel including a surface engaging the shoulder, and a central aperture receiving the second portion of the crankshaft and having a radius less then the radius of the first portion, and bolts extending through the flywheel and into the first portion of the crankshaft for securing the flywheel to the crankshaft.

Abstract: Disclosed herein is a marine propulsion device adapted to be mounted to the transom of the boat, the marine propulsion device comprising an engine, a rotatably mounted propeller, and a drive shaft assembly drivingly connecting the engine to the propeller, the drive shaft assembly including a lower drive shaft member having a lower end coupled to the propeller and having a threaded upper end, the drive shaft assembly further including an upper drive shaft member having a threaded lower end for threadedly engaging the threaded upper end of the lower drive shaft member.