Ethanol-laced fuel has changed some of the rules for winterizing marine gasoline systems. When prepping a boat for winter storage, boat owners must now do all they can to avoid phase separation — a phenomenon in which ethanol combines with water and separates from gasoline, descending in a soupy goop to the bottom of the tank. While this can occur at any time, it is more likely to happen when gas is stored for long periods.
The simplest solution? Avoid using gasoline with ethanol, if possible. There are a few outlets that dispense ethanol-free gas (boatingmag.com/pure-gas), but there may not be one nearby. If you can’t avoid ethanol (as most of us cannot), make sure the fuel contains no more than 10 percent, known as E10. Let’s focus on how to prepare such gasoline and related components in an outboard boat for winter.
Tools and Supplies
*TC-W3 two-stroke oil
*Engine oil and oil filter (for four-stroke outboards)
*New fuel filter elements
*Filter wrenches (to remove oil and fuel filters)
*Hex-head driver (for replacing hose clamps)
*Large slotted screwdriver (to drain lower-unit lube)
*Oil catcher to recycle old engine oil and gear lube ($19.95, oilfiltersonline.com)
*Cleanup rags (to wipe up spilled fuel, oil or gear lube)
1. Run It Down
Not all engine manufacturers today agree on how much gas to leave in the tank for winter. The answer also might be influenced by local fire laws and also by insurance rules (some of which specify full tanks for boats in storage yards). Our take? If the law allows, it should be close to empty. This way, if condensation and/or phase separation contaminate the fuel, there will be less bad fuel to dispose of.
2. Add Fuel Stabilizer in Advance
Gas lasts a couple of months before going bad. So pour in a new-age treatment to help prevent phase separation and stabilize the gas. These formulas include Lucas Safeguard Ethanol Fuel Conditioner, Sta-Bil Fuel Stabilizer, Star brite Star Tron Enzyme Fuel Treatment and ValvTect Ethanol Gasoline Treatment. Adding these in advance allows them to circulate through the fuel system.