The saddest stories of do-it-yourself boaters who winterize their engines usually begin with, “Man, I can’t believe I forgot to …” To ensure this doesn’t happen to you, the first thing on your mental checklist should be: Start a checklist. And the first entry should be a list of materials needed, so you can finish without making three trips to the store for supplies.
Get your stuff together. Be sure to include fogging oil; gear lube; fuel stabilizer; antifreeze for inboard/outboards; cleaning supplies; touch-up paints for the cowling and lower unit; lube oil; zincs, if needed; engine oil and a filter for four-strokes; tools to remove the prop, battery, spark plugs and gear oil screws; and, most important, your engine’s owner’s manual.
Read the owner’s manual. Many manufacturers have brand-specific procedures to follow. Outboards such as the Evinrude E-TEC have vastly different winterizing procedures, such as allowing the owner to fog the engine without leaving the helm seat.
Treat the fuel. There are two ways to go: Drain the fuel completely or treat it. Condensation will occur in an empty tank, but the small amount of water that will accumulate is manageable. If you go the full-tank route, make sure to fill it up to 95 percent with non-ethanol gas. Go to pure-gas.org to locate the nearest purveyor of unadulterated gasoline. As a precaution, I would still include fuel treatment that prevents the phase separation that can occur with ethanol-laced fuel, because you really don’t know what’s in the gas station’s tanks. Treat your fuel with STA-BIL or another stabilizing product, and run the engine for a few minutes before fogging it.
Change the oil. Old oil left in the reservoir of four-stroke engines can contain particles that can fuse to the engine’s interior if left undisturbed for the winter, so make sure to change the oil along with the filter.
Change the gear oil. Like they do in engine oil, metal particles can accumulate and damage the interior of your lower unit if it’s not drained. Also, water can be present and needs to go. When removing the screws, check the bottom one to see if excess metal shavings are present on the magnetized screw, which may indicate a problem that could warrant a trip to the dealer. Change the O-ring gaskets on the screws.
Flush it. Flushing your engine before storing it is always a good idea, even if you did it the last time you ran the engine.
See More Photos Remove all fuel from outboard engines. Disconnect the fuel line, and run the outboard until it’s out of fuel.
As the motor begins to stall, hit the choke a few times (if you have one) to keep it running as long as possible to excise the last fuel remnants. With I/Os and inboards, make sure you run the engine with stabilized fuel so it is present in all the lines.
Lubricate the engine’s cylinders. Fogging your engine will coat the cylinder walls, pistons and rings with oil in order to prevent rust from forming during your boating hiatus. If your engine has carburetors, spray the fogging oil directly into the intake while running it out of gas. If it doesn’t have carbs, remove the spark plugs one at a time and spray the interior of the cylinders. After spraying is completed, rotate the flywheel to evenly distribute the oil.
Clean and lube. Thoroughly go over the exterior of the engine and lower unit, cleaning dirt, oil and old lubrication. Remove any rust and use touch-up paint to restore the surface. Lubricate any moving parts, including control cables. Lightly treat rubber and metal parts with silicone spray, avoiding electrical connections.
Prep the prop. Remove the prop, remove old grease from the spline and re-lubricate. Keep your prop stored inside to discourage theft. This would be a good time to have it reconditioned by a prop shop if nicks and dings are present.
Drain it. Any water left in the interior of your engine will expand if it freezes, causing damage, so every drop must be evacuated. Storing the engine in an upright position will promote drainage. Take a pipe cleaner and probe every water outlet or pitot tube to clear any obstruction. For engines with closed cooling systems, drain the old antifreeze and replace it with a new 50/50 mix. Run the engine to make sure the new mixture is thoroughly dispersed.
Remove the batteries. Store your batteries in a dry location, and keep them charged throughout the winter. Your garage is fine, since cold temperatures won’t adversely affect a fully charged battery. Many boaters scrupulously avoid setting batteries on concrete for fear of damage, but other than the fact the batteries might get slightly colder, this is an urban legend.