Marine propulsion systems, intake air systems for marine propulsion systems, and marine propulsion systems having exhaust gas relief outlet

Abstract

A marine propulsion system is for propelling a marine vessel in water. The system comprises a marine vessel and an outboard motor that is coupled to the marine vessel. The outboard motor has a first inlet that receives intake air for combustion. A second inlet is located on the hull of the marine vessel and a conduit conveys the intake air from the second inlet on the marine vessel to the first inlet on the outboard motor. The system comprises an outboard motor that is coupled to a marine vessel, and that comprises an exhaust gas relief outlet that is located above the water when the outboard motor is at idle speed. A conduit conveys exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel.

What is claimed is: 
     
         1 . A marine propulsion system for propelling a marine vessel in water, the system comprising:
 a marine vessel;   an outboard motor that is coupled to the marine vessel and has a first inlet that receives intake air for combustion;   a second inlet located on the hull of marine vessel;   an intake conduit that conveys the intake air from the second inlet on the marine vessel to the first inlet on the outboard motor;   wherein the outboard motor has an exhaust gas relief outlet that is located above the water when the outboard motor is at idle speed; and   an exhaust conduit conveying exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel.   
     
     
         2 . The system according to  claim 1 , wherein the second inlet extends through one of a port and a starboard side of the marine vessel. 
     
     
         3 . The system according to  claim 1 , wherein the outboard motor is enclosed by the marine vessel. 
     
     
         4 . The system according to  claim 3 , wherein the marine vessel at least partially surrounds all sides of the outboard motor that are above the water. 
     
     
         5 . The system according to  claim 4 , comprising a hatch providing access to the outboard motor. 
     
     
         6 . The system according to  claim 4 , wherein operation of the outboard motor creates a negative pressure that does not affect pressure of the intake air received by the second inlet. 
     
     
         7 . The system according to  claim 1 , wherein the intake conduit comprises a flexible hose. 
     
     
         8 . The system according to  claim 1 , comprising a primary exhaust gas outlet that is located lower than the exhaust gas relief outlet on the outboard motor and that discharges exhaust gas to the water. 
     
     
         9 . The system according to  claim 1 , wherein the marine vessel comprises a hull and wherein the discharge outlet is on the hull. 
     
     
         10 . The system according to  claim 9 , wherein the exhaust conduit extends through one of a port and starboard side of the hull. 
     
     
         11 . The system according to  claim 10 , comprising a muffler receiving exhaust gas from the exhaust conduit. 
     
     
         12 . The system according to  claim 11 , wherein the muffler is located on the hull. 
     
     
         13 . A marine propulsion system for propelling a marine vessel in water, the system comprising:
 an outboard motor coupled to a marine vessel, the outboard motor comprising an exhaust gas relief outlet and a primary exhaust gas outlet that is located lower than the exhaust gas relief outlet on the outboard motor and that discharges exhaust gas to the water; and   an exhaust conduit conveying exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel;   wherein the exhaust conduit is sloped along its length so that water does not stagnate therein;   wherein the outboard motor has a first inlet that receives intake air for combustion;   a second inlet located on the hull of marine vessel; and   an intake conduit conveying the intake air from the second inlet on the marine vessel to the first inlet on the outboard motor.   
     
     
         14 . The system according to  claim 13 , wherein the exhaust conduit extends through the marine vessel at a location that is higher than the exhaust gas relief outlet and higher than the discharge outlet. 
     
     
         15 . The system according to  claim 13 , wherein the outboard motor is at least partially enclosed by a portion of the marine vessel. 
     
     
         16 . The system according to  claim 15 , wherein the portion of the marine vessel is an engine housing that surrounds all sides of the outboard motor that are above the water. 
     
     
         17 . The system according to  claim 13 , wherein the exhaust conduit comprises a flexible hose. 
     
     
         18 . The system according to  claim 13 , wherein the intake conduit comprises a flexible hose. 
     
     
         19 . In a marine propulsion system having an outboard motor coupled to a marine vessel for propelling the marine vessel in water, an exhaust gas system comprising an exhaust gas relief outlet that is located above the water when the outboard motor is at idle speed and a conduit conveying exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel, and an intake air system comprising a first inlet that receives intake air for combustion, a second inlet located on the hull of marine vessel, and an intake conduit conveying the intake air from the second inlet on the marine vessel to the first inlet on the outboard motor. 
     
     
         20 . The system according to  claim 19 , wherein the marine vessel comprises a hull, wherein the discharge outlet is on the hull, and wherein the second inlet extends through one of a port and a starboard side of the marine vessel.