DIY Outboard Motor Repair

by Steve Smith
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An outboard engine requires special fixes, and if you hire a mechanic to perform them, it can be costly. What's more, during the peak boating season, your local boat mechanics will be swamped with repairs. A wait for repairs is not uncommon, and that means missed boating opportunities just when you want to be on the water most. To avoid this, here are some DIY outboard repairs you can do on your own.

Fuel Additives

One thing you can do to repair an outboard motor that is suffering from several symptoms such as sputtering, hesitation at startup or the inability to start is to add fuel treatments. The most common is an ethanol treatment, which contains a chemical that offsets the condensation and water problems ethanol can cause in a marine engine that affect the performance of its parts. Adding this treatment to the fuel mixture before starting your outboard reduces this harmful effect and keeps the engine running smoothly. This maintenance step is critical if you're who fuel their boats with gas from a gas station and not a marina, because chances are there is ethanol in the gas station fuel.

Water Pump Disassembly

Removing and changing the water pump is another DIY solution. To remove a water pump, first locate it on your outboard engine by checking your user's manual. Loosen the exterior bolts that connect the pump to the housing. Remove the linkage with the appropriate hardware, typically a socket wrench and pliers. Disconnect the parting line by heating it with an oxyacetylene torch. Once this is removed, locate the brass pins and remove them.


To reassemble the water pump, repeat the above steps in reverse. Attach the hardware that connects the water pump, sliding in the pins in the appropriate places. Grease all the parts as you work to ensure a smooth fit and effortless operation. Then reconnect the parting line with the new hardware that is included with your pump. The housing is next. Grease all bolts around the housing and assemble it, then tighten the bolts with your wrench. Closely follow the installation instructions, as all models vary in design and installation methods.


Inspect hoses and gaskets around the outboard, particularly the fuel lines and primer bulbs, every few months. Check for cracks, tears and pinholes that often form, especially in fishing vessels. Stepping on these lines will cause microscopic cracks and tears, so even if you don't see any wear, replace them every season or two. This keeps the outboard running smoothly and efficiently and prevents gas leaks.

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