Compared to a car engine, a marine engine, especially an outboard motor, has a very rough life. Of course, it’s subjected to a lot of water (and sometimes saltwater at that) and it’s constantly being jostled around bumping up and down on the waves. Your average Yamaha outboard motor – especially the most powerful motors – has a much harder life than a car engine.

Unlike a car engine’s life which is measured in miles, an outboard’s life is measured in hours. It’s a little like the life of a lawnmower or tractor. In the past, your run of the mill outboard motor would only live to see about 800 to 1,000 hours before needing major work or an entire rebuild. Of course, there is no hard and fast number when it comes to hours.

These days, that’s not the case as boat engines have gotten more advanced, more efficient, and more resistant to corrosion. Now, a modern outboard motor’s lifespan can be measured in thousands of hours.

Keep up with maintenance

Mercury Marine The absolute most important factor for longevity is maintenance. Well maintained engines can log thousands, or even tens of thousands of miles because the operator is adhering to maintenance schedules borderline religiously. Keeping up with maintenance is the same reason you’ll see an old F-150, Chevy Tahoe, or Toyota Camry climb to 300,000 or 400,000 miles before complaining.

But not everyone relies on their boat engines professionally. For the average boater who just goes out on the water recreationally, a gas-powered marine engine will run for about 1,500 hours before needing a lot of work or a rebuild.

Still, new outboard engines like those made by Honda offer a five-year warranty for commercial outboard engines that cover anything catastrophic like a defect in the engine. Honda’s warranty is even transferrable if you’re buying a used engine. High-performance brands like Mercury Marine offer warranties of up to three years for its motors. The bottom line is, if you want your outboard motor to last, keep it maintained.