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Problems With Outboard Motors

Outboard motors experience a variety of problems. Outboard motor boat operators, however, can diagnose and correct most of these problems through some basic troubleshooting and simple repairs. In some instances, however, the particular symptom an outboard motor displays indicates the need for a more significant repair that requires having the boat serviced by a professional.

Sudden Stop

  • One problem that can occur with an outboard motor is a sudden stop when the motor has been running. This problem can have one of three different causes, including the operator having pulled out the emergency kill switch without realizing it. Overheating can also cause this problem, and such overheating might indicate water intake blockages or a faulty water pump. Another potential cause of this problem is fuel system problems, such as water in the fuel line, as described at the outboard-motors-and-boating-geraldton website.

Won't Start

  • A failure to start, which can have a variety of different causes, including fuel line problems. Other possible causes include a blown fuse, a loose connection to the starter key, loose spark plugs, corrosion of battery contacts, a detached kill switch and gears being engaged.

Vibrating Engine

  • Another outboard motor problem involves an engine that vibrates excessively while running. The causes of this problem can involve loose mounting bolts or clamp screws, a propeller corrupted by a foreign object or seaweed or a damaged or unbalanced propeller.

Running Rough

  • Sometimes, an outboard motor will operate but run roughly. This problem could indicate a lack of sparking in the spark plugs, as described at the outboard-motors-and-boating-geraldton website. Eroded spark plugs can come about through a poor fuel/oil mix, through water in the fuel, through a leaking head gasket, through overheating or through a bad or overloaded water pump.

Motor Coughs

  • An outboard motor that has been running can start to cough or miss, then stop running. Causes of this problem involve the fuel system, including running out of fuel. Other causes could be that the fuel air vent is not fully open, loose fuel hose connections, obstructions in the line and water in the fuel.


  • The propeller failing to turn provides another example of an outboard motor problem. Causes of this problem include debris fouling the propeller or propeller shaft, a broken shear pin and the gear selector not in the drive position.


  • The use of ethanol in outboard motor fuels also leads to a variety of problems. Ethanol reduces fuel emissions but can lead to increased presence of water in the fuel tank as well as lowered fuel economy, reports the Guide to Florida Bass Fishing website.