Boating Tips

Five Stupid Ways To Kill An Outboard

If you want your outboard to run, don’t do this!

Whether you run a massive Seven Marine outboard that cost as much as a Cadillac or a little 9.9 horsepower tiller-steer your brother-in-law sold you for a few hundred bucks, we can all agree on one thing: we want our outboards to run.

If you expect that eggbeater to keep on beating for years to come, be sure not to do any of these really, really stupid things that can kill an outboard.

outboard engines
Please, don’t kill me!
  1. Dry-starting the engine. Starting an outboard without a sufficient supply of cooling water is so damaging – yet so common – that we included this extreme error in our list of top Boating Blunders, too. The obvious danger is massive overheating, but the engine doesn’t even need to warm up for serious damage to occur. Not only is water used for cooling, but it’s also what gives the water pump impeller lubrication. Crank over the engine when it doesn’t have a water supply, and the impeller takes a serious beating. In fact, sometimes you can literally hear it whine as it spins dry, inside the pump housing. And if it gets seriously damaged you won’t have a clue, until the next time you launch the boat and use it. Hopefully, you’ll notice the tell-tale isn’t spitting out water, which leads us to number two.
  1. Running the engine when the tell-tale isn’t spouting water. Sometimes we simply don’t notice that the tell-tale has stopped pumping water, and other times we just want to ignore it. Truth be told, it’s fairly common for a clog to cut off the flow because of how little pressure runs through this system. After a false alarm or two, it’s also fairly common for people to ignore it. But in the long run, this is a stupid move. If your engine isn’t getting cooling water it’ll overheat in no time, and you’ll either have to call for a tow or risk melting hoses and belts.
outboard tips
Keep an eye on those tell-tales, and make sure they’re always pumping water.

If the tell-tale isn’t functioning, the first thing to do is take a few feet of stiff line in the 50# range and thread it up the hole. Every six or eight inches spin the line between your fingers and work it in as far as you can. Nine times out of 10, this breaks the clog free and the tell-tale starts spouting again. The tenth time, however, you won’t be able to get the flow going. And when that happens, running the engine is the last thing you should do.

  1. Shifting (with cable controls) when the engine’s not running. When an outboard engine isn’t running and you shift into and out of gear, the clutch dog may engage only partially. On top of that, the cables are intended to shift with the engine running and doing so otherwise can stress both the cables and the connections. If you shift into and out of gear accidentally when the engine isn’t running, leave the shifter in gear and spin the propeller by hand until you feel it “clunk,” so you know the gears are properly seated. Then, you can shift back to neutral and safely start the outboard. Bonus kill: shifting slowly and listening to the gears grind will also do a number on the lower unit.
  1. Filling up with ethanol-laden gas, and then failing to use a quality fuel additive. No-brainer here, people! That ethanol fuel you pumped into the tank has been deteriorating since the moment they mixed it at the refinery. If it sits in your boat for more than a week or two and you haven’t dosed it, you’re at risk of all kinds of ethanol problems. And fuel contamination is only one worry – with water in the system interior engine corrosion becomes a possibility, too. So make sure you put in a quality fuel additive (Techron Marine Protection Plus Fuel System Treatment is a good one) each and every time.
Techron Marine fuel additive
Don’t forget to add the additive, whenever ethanol is involved.
  1. Failing to freshwater flush the engine after each and every saltwater use. You’ve surely heard this one over and over again – because it’s true. Giving your outboard a freshwater flush after every single saltwater use is the single most important thing you can do to extend its lifetime. And conversely, failing to do so is a great way to slowly but surely kill that engine. If you’re not sure of how to flush your outboard before you take that boat out one single more time be sure to check out our Outboard Boat Motor Flushing How-To Video.
flushing outboard engines
Freshwater flushes are critical after each and every time an outboard engine is run in the brine.

The definition of “stupid” is (according to Mirriam-Webster) being slow of mind. Now, we know that since you’re a boat-owning fish-head, this isn’t an apt description of you and your brain. So don’t prove us wrong, people – and please, don’t kill that outboard engine!

Get more great boat reviews, boating information and tips from Lenny Rudow on BD.

Lenny Rudow
Lenny Rudow …has been a writer and editor in the marine field for over two decades, and has authored seven books. He is currently the Angler in Chie...