At The Helm:

Most older salts remember the good old days, several decades ago, back when you filled up your boat’s gas tank with whatever gas was handy, gave the starter rope a yank or the key a turn, and the outboard motor would fire right up and take them out fishing all day long and then home again without a care in the world. Like everything else in this world, everything changes and nothing remains constant, and that couldn’t be closer to the truth when we’re talking about outboard motors and marine fuel systems.
With the exception of one brand of outboard motor (Tohatsu/Nissan), who developed the first electronic fuel injected outboard motor about twenty years ago, ever since the advent of the outboard motor back in the early 1920s or so, all outboard motors were very simple 2-stroke carbureted motors, that ran on a mixture of gas and oil.
They didn’t have computers, throttle position or crank position sensors, no high or low fuel pressure or oxygen sensors, or anything as elaborate as today’s outboard motors. And for the most part, these basic machines just ran, and ran, and ran until they finally died after countless thousands of hours of use. Even then, they were fairly easy to re-build and get a second life out of them. Yes, those were the good old days for sure.
Now, let’s fast forward to the mid 1900s when gasoline refineries began to tinker with the gas they were producing, in order to develop more power for the big block automotive industry. They’d add this and that to the mixture to the point that it was hardly pure gasoline anymore.
Then, along came fuel shortages and environment activists, and that’s when the gas producers removed lead from our gas and started adding even more stuff to our fuels to gain higher mileage per gallon and reduce emissions. By the end of the 1990s and into the early 2000s, our beloved government’s Environmental Protection Agency had placed automotive emissions standards on the marine industry, which not only would mean even more exotic changes to our fuels, but also major changes to outboard motor designs and technology.
In no time at all, most outboard motor manufacturers were forced to leave behind their 2-stroke outboards, and scrambled to develop 4-stroke motors in order to meet these ultra-strict regulations.
Only two outboard manufacturers had a fairly easy time at this transition. Honda, which has always produced 4-stroke outboard motors, and Tohatsu’s (Nissan) very efficient EFI 2-strokes only required minor modifications to comply. As the new outboard motors made their way into the marketplace, fuels continued to be modified, and that’s when problems really started to happen.
It was around 2004 or 2005, when outboard motor technicians began seeing more and more fuel related problems with outboard motors, especially carbureted motors. Sure, gummed up carbs (and fuel injectors) were nothing new, but now there were so many a guy could make a fine living doing nothing but cleaning carbs and fuel systems. The reason was what many mechanics called “crapoline,” the poor quality fuels that no longer lasted very long nor produced the power of our good old gasoline from years past.
As a matter of fact, a good friend of mine who works in the fuels and lubricants industry, had told me that he’d be surprised if two-week-old gas would even burn. So to test his idea, we poured out some fresh gas on the concrete, and no matter what we did, we couldn’t make it burn.
He said that the only reason it worked at all in a motor was due to the high compression. Outboard manufacturers were doing their testing, too. Honda, using an independent lab, announced to their dealers that the tests showed that gasoline starts to break down in as little as two days!
Over the next couple of years, California’s environmental groups were at it again, now pushing ethanol down the throats of the government, automakers and EPA, and ultimately the general public. On the surface, the idea of adding ethanol (a type of alcohol) to gasoline made some sense, but as we all know now, it’s more detrimental than beneficial, and here’s why.
Ethanol, alcohol, is made from fermenting corn or other plants and was thought to be less expensive than fuels made from oil, but that ended up not quite being the case. While ethanol does burn cleaner than fossil fuels and it can be replenished, it doesn’t produce anywhere near the power of good old gasoline.
So, to obtain performance equal to that of straight gas, you’ve got to punch the throttle more, and by that time, the emissions are about the same, and you’ve spent more money doing it.
That aside, there’s another major problem associated with ethanol, and that’s its ability to draw water vapor, moisture, right out of the air. It doesn’t take a rocket scientist to know that water in your fuel is a very bad thing. Not only does water not compress, it also doesn’t burn and that reduces engine performance.
So, how much water are we talking about? Again, another lab test was conducted using 100 gallons of E85 (85 percent ethanol in gas) in a regular vented fuel tank. Their hydrometer test, (measures water in fuel) showed that after about one day, there was 6 percent (almost 6 gallons) of water in the fuel!
The worst part about ethanol’s ability to draw moisture out of the air is not the loss of performance, rather what it does to your fuel system and motor. Not only does ethanol permeate (pass through) right through metal, plastics and rubber, but the corrosive nature of water and ethanol is a mechanic’s dream come true, as it affects metal and plastic fuel tanks, fuel hoses, pumps, injectors and many parts of the actual motor. What outboard techs used to call “crapoline,” they now term it as “crapanol.”
Unfortunately, it’s almost impossible to find gas that doesn’t contain at least 10 percent ethanol. So, to help avoid downtime and enormous outboard motor repair bills, there are a few things that you can do. The first and most important step is to use only fresh gas in your outboard motor.
That means fueling up only at very busy gas stations that get frequent deliveries. Secondly, if you don’t use your boat at least twice a month, where the odds are that you’ll need to refuel, you should pump out any old fuel after around 30 days. You can still use that gas (not gas and oil mixture) in your car or truck as they’re not as picky as an outboard motor.
Next, despite whatever fuel or water filters your outboard motor may have, install a “10 micron fuel/water separator filter” in-line to trap the super fine dirt and water particles suspended in the ethanol, and change or drain that filter every 30 to 45 days.
Lastly, since standard fuel lines and hoses will crack and leak due to the combination of sunlight and ethanol in today’s fuels, to avoid air or fuel leaks and a possible fire onboard, replace all of your boat’s fuel and vent hoses with new one’s that were made for fuels containing ethanol/alcohol. Then…GO FISH!

AS ALWAYS, STAY SAFE & HAPPY BOATING!!!