Obsolete Outboards

by Max Wawrzyniak - St Louis, Missouri - USA   Winterizing

I am going to take a break from the series of columns on the 1956 Johnson 15hp to talk (write?) about a timely subject, at least for those of us living in the upper latitudes of the Northern Hemisphere: winter. It is just about time to "winterize" outboard motors to prevent damage during freezing weather.

During freezing weather, it is important that outboards be tilted "down" so that cooling water can fully drain. This is true for an outboard on a boat kept afloat and also for an outboard stored "land side." (click images to enlarge)

Most outboard motors are water-cooled, drawing water from whatever the boat is floating in (ocean, lake, river, etc.) circulating the water through passages (water jackets) in the powerhead, and then dumping the now-warmed water back into the ocean/lake/river/etc. Such a cooling system can not, of course, be protected from freezing temperatures by antifreeze as an auto's engine can. All post 1950 water-cooled outboard motors that I am aware of are designed so that the water jackets will drain by themselves (no help needed from you) when the engine is not running, as long as the engine is in a vertical attitude (i.e. tilted "down"). Usually if one's boat is kept in the water, it is better to "tilt-up" the outboard motor out of the water so that seaweed, slime, barnacles and other water critters will not attach themselves to the bottom end of the outboard, In freezing weather, however, one must always leave the outboard tilted down so that the water will drain from the waterjackets. If water is allowed to freeze in the waterjackets if is possible that the cylinder block can crack, resulting in an expensive repair to a newer outboard, and probably reducing an old outboard to "parts motor" status.

If your outboard is stored out of the water, either on the transom of your boat or on a stand in the garage, it is still important that it be stored in an upright position. If that is just not possible, then at least arrange for the motor to be upright for several minutes to allow the water to fully drain from the passages before it is placed in a horizontal position.

Leaving an outboard tilted up during the winter is asking for trouble. a water-cooled outboard will probably have water trapped in cooling passages, and a modern outboard with "through-hub" exhaust may suffer a cracked lower unit housing due to rain and snow collecting in the exhaust cavity in the lower unit and freezing.

Those with more modern outboards that feature "through-hub-exhaust;" (i.e. the engine exhaust exits the engine through the propeller hub) have another concern. If the motor is left attached to the boat and is tilted-up, and if the boat is out in the weather, it is possible for rain and snow to pass through the open propeller hub and to collect in the exhaust cavity at the rear of the lower unit, where it can freeze and possibly crack the lower unit housing. It is doubly important that outboards with through-hub-exhaust be tilted down during freezing weather

The next area of concern is the lower unit. Bad seals may have allowed water to leak into the lower unit gear case I have already laid out my opinions on leaky seals in the lower units columns so I will not address correcting that problem here. What I will stress is that is it very important that the lower units on ALL (new or old) outboard motors be drained and refilled with fresh lubricant before the onset of freezing weather. Just because your outboard showed no signs previously of water leaking into the lower unit does not mean that there is not water in there now. In addition to freezing and cracking the lower unit housing, water in the lower unit can corrode the plain steel gears and shafts and destroy the lubricating qualities of the lower unit oil.

Changing the lower unit lube prior to the onset of freezing weather is a simple job ANYONE can do; instructions were posted in the "lower Units" columns. Just have plenty of rags or paper towells handy; there is almost no way to do this job without making an oily mess. I use discount store lower unit lube but if your engine is much newer you should check the manufacturer's recommendations.

Often people will remove the drain and vent plugs on the lower unit and walk away, leaving the lower unit to drain and lay empty all winter. This is an invitation to corrosion of the gears and shafts, and of the ball/roller bearings in those engines so equiped. Drain the old lube, checking for signs of water. Water will either run out seperately, and look like water, or it may have combined with the lube, froming a "milkshake" like mixture. After the old lube has fully drained, refill the lower unit with fresh lube. If your engine is fairely new (1970's or newer) or is one of those funky 1960's/1970's OMC's (Johnson & Evinrude) fitted with electric shift or electro-hydraulic shift, then you need to be picky about what kind of lube you use in the lower unit, and I suggest following the manufacturer's recommendations. For the rest of the 1950's and 1960's OMC engines, I always use the "store brand" lower unit oil sold by a large chain of discount stores founded by a guy named Sam. And since the lower units on most of the 1950's outboards that I run mostly all leak to one degree or another, I am in the habit of changing the lower unit oil a few times during the boating season.

Instructions on changing lower unit oil can be found in the lower units columns and it is a simple, albeit messy job.

If your lower unit uses grease (such as the Lubriplate 105 that I have recommended in the past), you are not going to be able to easily change the lower unit lube. With these engines, I usually remove the drain/vent plugs and allow the engines to sit a few days, occasionally turning the flywheel so that the lower unit gears rotate some, and most of the water (if there is any) will drain. I will then "top-off" the grease in the lower unit and re-install the drain/vent plugs.

The next item on the winterizing list is usually "fogging" the engine. This usually means spraying an aerosol "fogging Oil" (sold as such) into the spark plug holes and then rotating the engine to distribute the oil around the cylinders. A better plan, but more difficult to accomplish, is to spray the fogging oil into the carburetor air intake as one "runs the gas out" of the engine. And then spray it in through the spark plug holes.

... water can combine with the lube forming a "milk shake" of contaminated lube.

I do not fog my engines. With a late model engine running on lean oil/ gasoline mixtures, the fogging oil is needed to protect the internal parts of the engine from corrosion. My old outboards carry 24 to 1 oil mixture recommendations from the factory, and I usually run them "richer," mixing the oil and gasoline at about 16 to 1. An outboard motor run on 16 to 1 is already pretty-well "fogged" in my opinion, so I don't see the need to inject even more oil into the thing.

Back in the mid-1980's, some OMC outboards came from the factory labeled for 100 to 1 oil/gas mixtures. OMC later altered this recommendation to 50 to 1 (which is what you should be running if you have one of these engines.) The reason for the factory changing the recommended oil mixture ratio was the issue of corrosion of internal parts during long periods of storage, and not issues of lubrication during running. Modern engines featuring oil injection often run on very lean mixtures at lower throttle settings, and fogging can be very important in protecting those engines, but be sure to follow the engine manufacturer's recommendations.

I already mentioned "running the gas out of the engine," which means simply that the fuel supply is cut off (remote tank hose disconnected/ fuel valve on internal tank closed) and the engine is run until it runs out of gas. This will empty the carburetor of most (but not all) gasoline. Gasoline allowed to sit in a carburetor for months can partially evaporate, leaving behind a gummy mess that require one to dissasemble and clean the carb. Another concern with the new ethanol-laden fuels is that the ethanol may attack the varnished cork floats used in the carbs of these engines. While running the gas out is a good idea, a better idea is to run the gas out, and then remove a tiny plug that most of these old OMC outboards have on the bottom of the carb float bowl so that the bowl can completely drain. Be sure to reinstall the plug.

While it has always been recommended that one use a fuel "stabilizer" additive in gasoline that one intended to store for long periods of time, say over the winter, I am now seeing recommendations that one ALWAYS use the stabilizer, due to the relatively short "shelf life" of the new ethanol-laden gasolines. Although I am not currently using a stabilizer for short-term storage of gasoline, I occasionally need to learn lessons the "hard way."

As I said, I never "fog" my engines. I had to search the whole shop to come up with a can of fogging oil to get a photo of. Found this can in the spider webs under the workbench. If you run your engine on oil/gas mixtures that are leaner than I use, fogging your engine might be a good idea.

That about covers winterization. The main things to remember are that the water jackets will not drain if the engine is horizontal, and that the #1 rule of outboard motor winter storage is changing the lower unit lube.

Happy Motor'n

Max

click here for a list of Columns by Max Wawrzyniak

Email this page to a friend