In board engines are contained within the hull of the craft, and the propeller is driven by a shaft that protrudes through the stern or hull.
Tools & Technique
To clean inboard engines, use an automotive cleaner such as GUNK, to remove grease and caked on dirt. Allow the hold to air for five minutes before doing any work within the engine compartment. Spray generously onto a cool engine, allow degreasers to work, then hose off sparingly with water, avoiding electrical wires, connections, and boxes. It is especially important on your boat to insure that visual signs of required maintenance such as paint, linkages, hoses, excessive rust can be seen. If a significant amount of water was used to rinse off the engine, be sure to run the bilge pump or pull the bilge plugs to drain excess water from the hull.