It has not been an especially good year for the 70-horsepower outboard that has occupied the transom of the 16-foot boat that is set under a tarp at the end of the driveway.
The starter went bad and was rebuilt. The in-line fuel bulb developed a minuscule leak and was replaced. The spark plugs, FTC seems, have been replaced more often than in past years. But, then, it has been in saltwater and freshwater use for 10 years and one has to expect that parts will go bad.
All in all, 10 years is not a bad lifetime for a chunk of milled aluminum -- and with basic storage preparation, I fully expect that next spring, with new fuel in the tank and a fresh charge on the battery, the three-cylinder Mercury again will rumble to life and run reliably through another season.
In many respects, winter storage is a key element in outboard maintenance. Proper storage will protect the motor from rust, corrosion and dirt infiltration in carburetors, fuel lines, etc.
Assuming manufacturer's recommendations for normal lubrication, freshwater flushing and proper fuel mixture have been adhered to during the season, and external lubrication points have been serviced at the end of the season, preparation for storage is simple and brief.
The following is the process I follow each fall (for other outboards, the steps will be similar, but it is a good idea to purchase and study a shop manual for your model before breaking out the wrenches and screwdrivers):
* Remove the cowling, the outer cover and then the sound box from the motor.
* Using a water muffler, a device that hooks to a garden hose and clamps over water intake screens on the lower unit of the motor, start the engine and let it warm up. Be certain that water is moving through the hose to the motor and out. Do not rev the engine.
* Once the engine is warm, disconnect the fuel line from the engine and slowly pour about two ounces of storage seal (for Mercury outboards, Quicksilver Storage Seal is recommended, but there are various similar products on the market) into each carburetor. Let the engine run until it stalls. Stalling indicates a dry carburetor and a good seal.
* Remove the spark plugs individually, taking care to clear any loose matter from the plug well before loosening the plugs, and spray an ounce of storage sealant into each cylinder through the spark-plug holes. With the plugs still out, turn the flywheel manually for several rotations to distribute the sealant. Reinstall spark plugs.
* Clean the fuel tank filter by detaching the line from the tank and removing the fuel pickup tube. Cleanse the wire-mesh filter in new solvent. Blow it dry with compressed air.
* To service the engine fuel filter, purchase the appropriate O-ring gasket. Assuming you have that in hand, remove the cap from the filter assembly, remove the O-ring and discard it. Clean the mesh filter in new solvent, and blow it dry with compressed air. Reinstall the filter cover with the new O-ring.
* Clean the water-pickup screens with a piece of stiff wire, and then use compressed air to blow out the residue.
* Check to be sure that all water drains are clear. Water left in the system will expand when it freezes and can cause major damage to gear housings or the water pump.
* Clean the motor thoroughly with a soft, clean cloth. Spray the motor with a rust and corrosion inhibitor, reinstall the cowling and cover all painted surfaces with a thin film of clean oil.
* Remove the propeller, and relubricate the shaft with the appropriate sealant. Reinstall the propeller.
* Drain the fuel tank. After 60 days, under ideal conditions, fuel becomes basically unusable, even with the addition of stabilizers. Empty the tank, and refill with new fuel in the spring.
* The last chore is to service the battery (always disconnect the negative cable first). Clean the surface of the battery case. Check the electrolyte level in each cell, even on so-called maintenance-free batteries. Top off to 3/16-inch above the baffles with distilled water. Lubricate the terminals and terminal bolts with grease. Put the battery on a charger until it is fully charged, and store where it will not freeze. In midwinter, check the battery and recharge as necessary. Next spring, remove the excess grease from the terminals before installing the battery in the boat.