How to Troubleshoot Outboard Problems

by Ross Glyn

Outboard motors are tough and hardy. They put up with harsh elements and still keep running. However, eventually wear and tear will get the better of them. Usually, the problems are fairly simple to remedy, whether the issue is with the fuel system or an oil leak. For more serious problems, have a qualified marine mechanic check out your outboard motor. In the meantime, there are a few basic troubleshooting steps you can run through.

Check the spark plug for excessive dirt or corrosion if the outboard motor will not start. Replace the plug if necessary.

Inspect the motor gaskets, or seals, for any damage or cracks. The gaskets are the thin layer of seal between the engine components that prevent liquids and fuel from leaking out. A damaged gasket can create a vacuum leak in the motor. Check the fuel pump cover for any damage as this could also be the cause of a vacuum leak.

Check that the fuel tank has fuel in it and fill it if necessary. Even if there is a small amount of fuel, fill the tank. Ensure that the fuel lines are free of damage and leaks. Press the rubber fuel primer bulb. If you feel resistance, there could be a problem with the fuel line assembly. Have a qualified marine mechanic check this out for you as fuel may not be reaching the motor and the fuel line assembly may need to be replaced.

Use a compression gauge to check the motor compression. Attach the gauge to the system and check the reading. A normal reading should be between 60 and 90 PSI. If it is lower than this, have a mechanic check this over for you.

Remove the plastic motor cowling and check for any oily residue. If you notice oil, this could indicate a problem with the rings. Have a mechanic investigate this further.


  • check Drain the lines and carburetor when storing the boat for the winter. This will prevent fuel problems in the future. Fuel that is older than 30 days can become contaminated and will cause difficulties with starting the outboard motor.
  • check Use a fuel additive to clean the carburetor. Make sure that it is approved for the engine you are using as certain additives and cleaners can cause damage to the system.

Items you will need

About the Author

Ross Glyn began writing for film and television in 1986. He wrote and directed the film “After The Rain” as well as the play “Soweto's Burning.” He is a member of the Writers Guild Of America, the Screen Actors Guild and the American Federation of Television and Radio Artists. Ross holds a performer's degree from the London Academy of Music and Dramatic Art.

Photo Credits

  • photo_camera toy outboard motor image by pearlguy from