Seven Steps to Keep Your Outboard Kicking
A good flush and an annual application of grease and oil are just what the doctor ordered for small engines.
With the fuel, cooling, and lubrication systems taken care of, it’s time to think about engine corrosion a bit more.
All small engines have sacrificial anodes mounted on the lower gear case and sometimes on the lower section of the engine-mounting bracket. These should be inspected and, if they’re depleted by 50 percent or more, replaced. (The photo at right shows a mounted anode that’s still serviceable for at least another season.) The best material to use for the replacement anodes is a specialized aluminum anode, not zinc. The aluminum provides the best service in salt, brackish, and even fresh water. Zinc only performs at its best in a saltwater environment.
It’s now time to fog the cylinders.
Engine fogging oil is available at all automotive-and marine-supply outlets. With two-stroke engines, it used to be considered best to remove the carburetor air-intake cowling and run the engine while simultaneously spraying the fogging oil into the respective carburetors until the engine sputtered to a stop. Over the years, though, I’ve found this method to be messy. And problematic: I say this because the oil can cause the carburetors to get gummed up inside, a problem you’ll discover when you take the engine out of storage.
Since two-strokes get their lubrication from the oil in the gasoline, as long as the oil/gas mix ratio is correct, I don’t worry about the engine’s internal components getting a fresh coating of lubrication; it happens naturally when the motor is running. Some engine mechanics recommend adding a slightly richer mix of oil and gas for the final run before the engine gets put to bed for the winter. Fair enough, and no harm done; just don’t overdo it. For example, a 25-to-1 ratio vs. a 50-to-1 ratio of gas and oil really won’t hurt anything and won’t gum up the carburetors.
But there is a use for fogging oil in both two- and four-stroke engines. Remove the spark plugs and spray the fogging oil into each cylinder for a few seconds, preferably while turning the engine over with the pull-start cord. This will provide a nice corrosion-inhibiting oil film to protect the engine cylinder walls. Replace the spark plugs if needed. I usually get several years out of a set, and even then they would probably last longer, I just replace them to ensure reliability.
Do you recall that we removed the propeller when we began? Now’s the time to inspect the propeller for dings or dents and to replace it if needed. Also, it’s time to inspect the prop shaft for any fishing line that may now be wrapped around it; it should all be removed. Left unattended, line will destroy the shaft seals and allow water to migrate into the gear case or oil to leak out of the gear case. Either way, expensive damage can be the end result of leaving line there.
It’s a good idea to wipe the old grease off the propeller shaft and apply some fresh grease to the shaft before you reinstall the propeller.