The present invention relates to an outboard drive device (10) comprising an outboard motor (11) having a crankshaft (16), wherein said outboard drive device (10) further comprises a propeller which propeller is below the hull (13) of a boat when said outboard drive device (10) is operated, and a power coupling system for transferring power from the motor (11) to the propeller. The power coupling system comprises a power transfer device (17) for transferring output power from the crankshaft (16) to a transmission drive shaft (19) of a transmission (18), and a power transfer means (20) for transferring output power from the transmission (18) to a drive shaft (21) of an endless loop flexible drive coupling (22) operatively connecting said transmission (18) to a propeller shaft (12) for driving said propeller, wherein the crankshaft (16) is substantially horizontal and substantially parallel to the propeller shaft (12) when said outboard drive device (10) is operated. The invention also relates to a method of manufacturing said outboard drive device (10).