As we approach winter, we need to prepare our boats for several months of idling away in the marina slip or on the driveway, waiting for the next season of fun and frolic on the water. Our goal, whether we own an inboard engine on a fairly large vessel or one or more outboard motors, is to prevent corrosion, and in mountain areas that freeze over the winter, damage from expansion of frozen water.
Outboard Motors
The first step in preparing an outboard motor for storage is disconnecting the rubber fuel line and, depending on the type, draining fuel into a jerry can. Let the line dry out for at least an hour to prevent flammable gasoline vapors from forming inside the line.
If you are preparing to stow the outboard motor in your garage or other closed space, allow air to circulate around the engine throughout the offseason. Again, we are trying to prevent gasoline vapor from accumulating in a closed space.
If you have a small outboard motor that has been used in saltwater, use a wooden or plastic mount on a trash can full of fresh water to run the engine for several minutes, clearing the water pump and internal tubing from salt. This will add years of service to the water pump, impeller and aluminum casing of the lower unit. Larger motors have either flush-out ports where you attach a garden hose or flush-out muffs to rinse out the cooling system.
Next, wipe down the engine with a wet sponge and liquid soap to remove gasoline, dirt and caked motor oil from the surface of the motor and surrounding area and then rinse with water. Also wash off the lower unit, including the propeller.
Look for frayed cables and, if the outboard has a starter motor, wires and electrical connections. Make sure to tighten wire connections if necessary and attend to any other necessary mechanical repairs before storing the motor for the winter. You don’t want to discover problems after a long drive to the Colorado River, where you might have difficulty finding parts, tools and professional services to make the necessary repairs.
Inboard Engines
Inboard gasoline engines on trailer boats are somewhat similar to those in automobiles, except the transmission and lower unit require more frequently scheduled maintenance. This type of engine generally requires a change of oil and filter every 100 hours and its cooling system should be drained and refilled with antifreeze in the same time frame.
Permanently installed gasoline and diesel engines in ocean-going vessels follow more or less the same rule for oil changes, but because of their constant exposure to saltwater, there are important steps to remember not just during the winter months, but all year round as well. During winter, when our boat in the marina slip is getting very little use, we need to remember the constant need for corrosion control.
The main nexus for saltwater intrusion and corrosion is in the heat exchanger mounted on the engine. If the coolant reservoir is at its normal level and has its normal, yellowish color, then the unit is probably free of leaks. If the level is abnormally low and cloudy, there is likely a leak between the core and the tank requiring immediate attention. Check the level every few weeks during winter to ensure the health of this vital component of your inboard engine.
Also check the bronze valves on the fuel line to verify there are no leaks, nary a drop, along the fuel line. If you find a leaky valve, shut off the main fuel valve at the tank and switch out the faulty valve – especially if you have a gasoline engine. Imagine gasoline dripping out into the cabin while you are away – all it takes is one little spark!
If the engine needs a change of fuel and oil filters, doing this before the winter sets in will save you time in the spring when you will be itching for fun in the sun. Changing the oil and filter should be a fairly straightforward process. Depending on the manufacturer and type of oil system, there should be some means of pumping out the oil without having to drain it into a pan. If you do need to drain engine oil into a pan, wipe up any spilled oil before it oozes into the bilge, where the oil will be pumped out into the water outside, a major no-no.
When changing the oil filter, lay out a heavy piece of canvas or plastic to catch oil drips before they fall into the bilge. As with an automobile, smear a thin coat of clean oil on the rubber gasket to ensure a perfect seal against the mount on the engine.
A fuel-filter system in a boat with an inboard engine normally has a pre-filter with a water separator mounted away from the engine, plus a secondary filter mounted on the engine itself. Follow manufacturer guidelines for regularly scheduled fuel-filter changes to guarantee you have an engine that will start on the first turn of the key while away from the marina.
Some of us assume the transmission, or gearbox, tends to itself dutifully after an eternity of running hours. To avoid problems down the line, change the transmission fluid after the number of hours recommended by the manufacturer. In most cases, when a boat engine transmission fails, the only workable solution is a new transmission.
Finally, inspecting and adjusting the packing gland where the propeller shaft passes through the hull is essential to keeping your boat afloat. Allow a small amount of water ingress to keep the shaft from becoming oxygen-starved, which can result in crevice corrosion, loss of the prop shaft and ultimately, sinking of the vessel. While this is extremely rare, “an ounce of prevention is worth a pound of cure.”
Whether your boat spends most of its life in or out of the water, taking proper care of its drive train and following a schedule of regular maintenance will yield years of fun and excitement.
