Patent ID: 7452255

Claim:
An outboard motor including a casing housing an engine, a driveshaft extending downwardly from the engine, a propulsion device coupled with a bottom end of the driveshaft, an exhaust passage extending from the engine to an external location through the propulsion device and extending through the casing housing, and a cooling water passage for cooling the engine by cooling water introduced thereinto from outside, wherein the casing housing includes an outer wall and an inner wall unitarily coupled with each other so as to define a double wall structure on both a starboard and port side of the exhaust passage, and wherein a water guiding passage extends between each set of the outer wall and the inner wall to cool the casing housing, wherein each water guiding passage includes a jacket section defining an internal cavity which is configured to accumulate a portion of the cooling water, each jacket section having a cooling water inlet positioned at a lower portion of a front end or a rear end of the jacket section, and each jacket section having a cooling water outlet positioned at an upper portion of the remainder of the front end and the rear end of the jacket section.