For boaters, nothing ruins a day on the lake quicker than being stuck at the launch or stalled in the water troubleshooting an engine issue.

Marine engines, just like the engine in your car or truck, require routine maintenance to run properly. And the engine on your boat likely doesn’t run nearly as frequently as your car or truck engine, making it more susceptible to a bunch of issues that can cause frustration when it’s time to hit the lake.  

But fear not — with a little know-how, you can keep boat engine issues at bay, and focus on enjoying your time on the water.

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A marine engine can suffer from a wide range of problems, just like an automotive engine. The root of those problems is generally the same as well: fuel, air, and spark. If your battery wasn’t charged during storage, it might be dead (spark), you might have the bad luck of finding a mouse nest in your intake (air), or old gas might have wreaked havoc on your fuel system. 

These are just a few examples. Let’s look at the most common engine symptoms you might experience, what they mean, and what you can do to prevent or fix them. 

Hard Start or No Start

If your battery is good, your engine should turn over once you press the ignition button or turn the key. Assuming that happens, but your engine doesn’t start, you’re looking at (as stated above) a fuel, air, or spark problem. Make sure your air filter isn’t clogged, check your spark plugs for fouling and make sure your plug wires are properly connected. And make sure you are using fresh gas. Most fuel has a shelf life of about 30 days. After that, it begins to break down, losing volatility and forming varnish and deposits that can clog fuel passageways.

Sputtering, Surging, or Low Power

If your boat’s engine is running rough — sputtering, surging, or losing power — it’s likely you have a fuel system issue. A clogged fuel filter is a common culprit. It’s a good idea to check your fuel filter before heading out and to carry an extra one with you in case you need to change it on the water. An obstructed fuel injector or carburetor jet could also cause these problems. Or, you might have a dirty air filter.

It’s possible that a loss of compression from a more significant mechanical failure is to blame for your rough-running engine, but it’s best to check the simple things before tearing into your engine or calling your mechanic.


Unlike automotive engines, boat engines most commonly use the water they’re floating on for cooling. If an intake port is clogged, water won’t be able to circulate and your engine will get too hot, leading to failure. Check for weeds or other debris in your cooling ports. If they are clean, you might have a loose or cracked cooling hose.


Your boat, just like your car or truck, needs routine maintenance. Regularly check engine parts that incur wear and tear, or are expected to need replacing after certain intervals, based on recommendations in your owner’s manual. Create a maintenance checklist and be sure you follow it each season, especially before you get on the water for the first time.

SEA FOAM MARINE PRO helps your marine engine run smoother and last longer!

Sea Foam Motor Treatment works to clean injectors and restore factory spray patterns. It is safe and effective for all types of gasoline fuel injection systems. Using Sea Foam Motor Treatment in your gas is also a good way to ensure all components of your fuel system stay clean and perform their best.