This boating season, and depending on how you handle it, fuel will either be a nagging problem or no problem at all. Here’s what you need to know, along with a few tips on keeping
your boat running strong all season long. It’s no secret alcohol-laced gasoline creates a boat load of problems including absorbing moisture out of the atmosphere. There’s also the fact that E-5 through E-85 gasoline shelf life is notoriously short. After about a month’s time the petrochemical begins to degrade into nasty gum and varnish that clogs up fuel injectors and carburetor passages.
Obviously it’s common sense to avoid alcohol altogether. Do that by scouting out marinas that sell unadulterated gasoline. Ask around. That said, it’s understandable that trailer boaters are tempted to pull up to a land-based gas station to top off with the less expensive road tax Regular gas. But whenever you use automotive fuel, be sure to dose the gasoline with marine-specific stabilizer before you start pumping. And no matter what the brand name of the stabilizer, before you even open the can, read the label and follow its instructions to the letter. Know that in general, the greater the concentration of stabilizer – the number of ounces added per gallon of gas – the longer the protection before it begins to sour.
It’s also important to know that alcohol fuel burned within three weeks, with or without stabilizer, tends to be problem free and for the same reasons your tow vehicle doesn’t have an issue with the stuff. The passage of time is the enemy of E-10 and E-15. Figure on a shelf life of about three to four weeks before the fuel rots and water seeps in. Meanwhile, back at the waterfront know that some fuel docks rather considerately treat their gasoline supplies with stabilizer (sometimes this means gas with alcohol – sometimes alcohol free) which means that when you top off dockside you don’t have to go to the trouble or expense of popping the top on your own chemicals.
No matter what the fuel source one must-have accessory item is a fuel/water separator, even on those portable outboard motors rated from 2 to 30 horsepower. Costs for a portable outboard motor sized fuel/water separator filter start at about $30 and replacement elements cost about $15. An element should last a whole season, or about 100 engine hours. Also good to know, on these miniature water/separator/filters, the filter element proper is a tightly woven 10 micron mesh that keeps tiny bits of gum (decomposing gasoline) and other particulate matter from clogging up a small outboard motor’s tiny main jet and passages. And because alcohol is corrosive, it’s pretty hard on all fuel system components. Likely as not the day will come when you squeeze the fuel primer bulb and watch in absolute horror as the contents of the bowl turn black in a swirling cloud of miniscule rubber particles. That the telltale sign that the primer bulb has rotted on the inside and may soon crack wide open and spill fuel. Imagine what would have happened if the rotten rubber had flowed to the fuel injectors or carburetor jets and you didn’t have the foresight to install a filter. You may also find little yellow flecks of yellow plastic which are the broken down remains of the fuel hose liner.
On larger boats with either gas or diesel engines it’s also a good idea to have a competent fuel cleansing system that begins at the fuel dock. Consider pre-filtering, or pumping fuel into a screened fuel filter jabbed into the fill tube. Its specially coated wide mesh screen not only keeps big junk out of the tank, but also separates out any free-standing water. The water drops down into a sump and is disposed of in an environmentally friendly manner. The first time you try one of these out you might be shocked at how filthy fuel can be. If your boat is diesel powered you probably already know about the fuel additives that kill microbes, the living breathing organisms that would otherwise thrive in diesel fuel. Kill them so they don’t proliferate and damage the fuel system. Once again, read the label and wear gloves to protect your skin.