Patent ID: 9308980
Filing Date: 2016-04-12
CPC Classification: B63H

Claim Text:
1. An outboard motor comprising: an internal combustion engine; an adapter plate that supports the engine; a driveshaft housing that is suspended below the adapter plate; a lower cowl that surrounds the driveshaft housing; a lower cowl volume that is defined between the adapter plate, the lower cowl and the driveshaft housing; a lower cowl volume inlet that is configured to supply relief exhaust gases to the lower cowl volume; and a lower cowl volume outlet that is configured to discharge the relief exhaust gases from the lower cowl volume to atmosphere surrounding the outboard motor; wherein the lower cowl volume is configured to cause expansion of the relief exhaust gases prior to discharge of the relief exhaust gases to the atmosphere without passing through an intervening labyrinth structure; wherein the exhaust tube is configured to discharge the exhaust gas to an exhaust gas volume that is located below the lower cowl volume; and wherein the exhaust gas volume is at least partially separated from the lower cowl volume by the driveshaft housing.