Boat Motor Troubleshooting

by Jackson Lewis

Anyone that owns or rents motorized boats has likely found himself stranded at some point in his experience on the water. A fundamental understanding of basic boat engine troubleshooting and repair is essential for any serious mariner in order to avoid significant towing fees over the life of one's boat. Taking time to learn basic boat motor repair will alleviate many common issues that result in stranded boats requiring expensive tows back to the marina or dock.


Marine boat engine repair and troubleshooting is done at two levels: by the owner and by a repair activity. Many times, owners will have their boat fail to start at the marina or fail while running at sea or on the lake. The ability to conduct basic troubleshooting and repair is significant for the boat owner in order to reduce costs for correcting issues that do not require an outside activity to repair.


Boat engine troubleshooting is primarily used to get a dead boat engine running again so that further examination can be conducted ashore to see if greater repairs are required to fix the engine. Common issues for boat owners to troubleshoot are overheating, the engine won't start or stops running, the motor will run but not go into gear and running aground.


The four basic types of boat motor troubleshooting have basic steps to conduct for troubleshooting. For an overheating engine, the following steps should be conducted prior to asking for professional assistance. First, inspect the hoses, sea cock, sea strainer and water intake for blockage. The sea cock can sometimes be closed, or there could have been other debris blocking the lines. Next, inspect for a loose or broken belt on the water and circulation pumps. Then check the coolant and top off if low or out and check the engine oil and add as required. Finally, inspect the water pump impeller and if destroyed or damaged replace the impeller. For an engine that fails to start or stops running, first inspect the fuel filter for significant dirt or water and replace if required. Next, inspect the distributor cap for water and, if necessary, wipe with with WD-40 when the engine is cool. Inspect the ignition fuse, wire harness plug and the reset button for the engine. Replace the fuse, reset the ignition box and ensure all connections are firm and free of dirt and debris. Inspect the battery and switch to the secondary battery or both battery positions. Then verify the fuel supply hose is not twisted or kinked, and finally, confirm the fuel tank vent screw is open.


Other motor repair issues that can arise are if the boat motor will run and not go into gear or if the boat owner runs the vessel aground. For a motor that will run but not enter gear, check the boat prop for fouling and remove the rope, line or other object fouling the propeller. Inspect the hub on the prop and replace if worn. Finally, verify the transmission oil and add oil if required. For running aground, verify that the bilges are not being filled by water leaking through a hull intrusion. Next, drop the anchor to keep from moving aground further and to avoid greater damage to the hull. Finally, request towing assistance as close to high tide as possible.


Boat motor troubleshooting and repair is not a task that has to be done by a major repair facility. By taking basic troubleshooting steps, many of the common problems that plague boaters at sea and on freshwater lakes can be resolved. These actions benefit the boat owner by saving money on towing and outside activity repair when not necessary.

About the Author

Based in Memphis, Jackson Lewis has been writing on technology-related material for 10 years with a recent emphasis on golf and other sports. He has been freelance writing for Demand Media since 2008. Lewis holds a Master of Science in computer science from the United States Naval Postgraduate School.

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