Water cooling system for an outboard jet drive marine propulsion system

Abstract

An outboard jet drive marine system for a boat includes a housing. An engine is disposed within the housing. A jet drive unit is disposed within the housing parallel thereto and operatively coupled to the engine. A cooling system is mounted to the housing, outside the housing, and below the water line when the housing is disposed in water during operation. A fuel line operatively coupled to the engine for providing fuel thereto. The fuel line provides fuel heated by the engine into the cooling system.

1 . An outboard jet drive marine system for a boat comprising: 
 a housing;    an engine disposed within said housing;    a jet drive unit disposed within said housing parallel thereto, and operatively coupled to said engine;    a cooling system, mounted to the housing outside the housing and below the water line when the housing is disposed in water during operation; and    a fuel line operatively coupled to said engine for providing fuel thereto, said fuel line providing fuel heated by the engine into the cooling system.    
   
   
       2 . The outboard jet drive marine system of  claim 1 , wherein said cooling system includes a chamber for cooling the fuel.  
   
   
       3 . The outboard jet drive marine system of  claim 1 , wherein said cooling system includes a chamber, said chamber being mounted to an outside surface of the housing, and further comprising an inlet in fluid communication with said chamber, said inlet being mounted within said housing and an outlet in fluid communication with said chamber, said outlet being mounted within the housing.  
   
   
       4 . The outboard jet drive marine system of  claim 3 , further comprising an outlet tube, said outlet tube extending from said outlet to within said chamber, said outlet tube being in fluid communication with said chamber and said outlet.  
   
   
       5 . The outboard jet drive marine system of  claim 4 , wherein said chamber has a height, outlet tube extends for a depth within the chamber, said depth being at least one half the height of said chamber.  
   
   
       6 . The outboard jet drive marine system of  claim 4 , wherein said outlet tube extends through said inlet, the outlet tube not being in fluid communication with said inlet.  
   
   
       7 . The outboard jet drive marine system of  claim 1 , further comprising an injection pump for pumping said fuel to said fuel cooler; and said fuel line including a return line for returning the cooled fuel to the engine.  
   
   
       8 . The outboard jet drive marine system of  claim 7 , further comprising a fuel filter disposed between said return line and the engine.  
   
   
       9 . The outboard jet drive marine system of  claim 1 , wherein said cooling system is attached to a rigid inflatable boat.  
   
   
       10 . The outboard jet drive marine system of  claim 1 , wherein said outboard jet drive marine system is attached to a boat having a length of about 30 feet or less.  
   
   
       11 . The outboard jet drive marine system of  claim 1 , wherein at least a part of the chamber is formed from a thermally conductive material.