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Dingy (and other) Motors, Part Two
by Peter F. Ten Haagen
4) Check the gearcase for signs of water intrusion at least once a season. Place the motor in a vertical position and remove the bottom drain plug on the lower unit and collect the sample of the oil in a suitable container. If there is water present, it will appear immediately. If the engine has been run recently and is leaking water, the normally black lower unit oil will appear creamy, more or less coffee colored. If you discover this condition you should have the lower unit serviced by a professional shop as soon as possible to prevent corrosive damage to the gears inside. If you are buying a used motor and use this method to test the condition of the lower unit and you find clean, fresh oil insist on running the motor on a boat for an hour or so and check it again - someone may be trying to hide something. For engines used seasonally, the lower unit oil should be changed prior to putting it into storage - this gives you an edge if you do find water intrusion in that you can have the situation dealt with in your off season, and also prevent that water from hanging around on your gears all winter long. For motors in year around use the oil should be changed at least every six months. Lower unit repairs can be VERY expensive, and maintaining the oil is cheap insurance. 5) Gas/oil mixture. Try to keep yourself honest in measuring the oil you mix into the gas for your two stroke engine. When in doubt, err on the side of adding a little too much oil to the mix. Larger motors are usually equipped with oil injection systems which meter the oil the engine needs at various throttle and load settings, a handy system enjoyed by motorcyclists for decades - still, you must check the level in the oil tank on a regular basis, either based on engine hours or routinely when you add gasoline to the tanks. Warning lights and buzzers are fine when they work, but such devices have been known to fail so keep tabs on the oil reservoir as a matter of course - this of course applies to 4-stroke engines as well. 6) Cooling system. Keep the cooling system=s Atattle tale@ hose clear of obstructions and use it to monitor the waterpump=s activity. Of course, this is not an easy thing to do since your attention will generally be focused on where you are heading, as opposed to over the transom to watch the water coming out of your outboard. It would be helpful if manufacturers would come up with a way of making this stream more easily monitored than by firing it out the back or the side. If you do detect a loss of water flow, or steam coming from the motor indicating it is over heated, stop immediately and address the situation. Weeds and plastic bags can cover the water intakes of your motor and stop the cooling system from functioning, and water pumps can wear out and lose vanes rendering them ineffective at higher speeds. Overheating can cause serious engine damage, so pay attention for the signs of a problem. It is a good idea to carry a waterpump rebuild kit when traveling away from home, and to have the waterpump replaced about every second year of service even if it appears to be functioning fine. Inactivity is no friend to a waterpump impeller by the way, as it can cause the vanes to take on a Aset@ and not pump efficiently or even break off when the engine is run again. 7) Fuel tanks. Metal ones want to rust, so use a good caulk to install a rubber bumper on the base to keep the salt water away from the steel (a piece of split hose can work for this purpose). If your tank is plastic, the sun=s UV radiation will degrade it over time so keep it under a seat if you can. Check it from time to time for signs of breakdown and replace it well ahead of it developing cracks or brittleness. Another fuel note: beware of water in your outboard fuel tank. The best defense is a fuel water separator installed between the tank and the engine, but this is not always practical. However you can install a see-through in-line filter under the hood. If you check it regularly you can spot water accumulating before it gets ingested into your engine, saving an expensive carburetor overhaul. Another defense is to take fuel on via a gas can which you can then pour into your outboard=s tank - with plastic ones you can generally see water if there is any lying under the fuel. 8) Odds and ends. If you own an outboard motor you should own a grease gun. Hit the grease nipples regularly - a little grease now and then beats a whole lot of grease all at one time - I like synthetic grease. When you check your spark plugs, spray a little WD-40 into the ignition cable ends to displace moisture before reinstalling them on the plugs. Keep the motor tilted up as much as possible, especially overnight to prevent the accumulation of marine growth in the water intake and internal plumbing. 9) One final point. If you use the same outboard as the auxiliary power for your sailboat and to buzz around in your planing inflatable, you will need to carry two propellers. The prop designed to push your sailboat at 5 knots may not plane your dinghy, and the prop that planes the dinghy may cause the motor to labor and damage itself when pushing the big boat. A small outboard motor is a very convenient power package which can perform a number of valuable services and last a decade or more with thoughtful use and maintenance practices. Treat it like a member of the family! It sure beats rowing. |