Revving your engine


The life of a sportsman can, at times, be a complicated lot. With all the equipment that is necessary to pursue our favorite sports, it’s a wonder that we keep it all going.

Like most sportsman who own an outboard motor, mine first sees action in the early spring when the ice goes out and the salmon start to feed. Next, it’s on to more trolling for brown trout in May. After two months of cold morning starts and slow-speed trolling, it sits idle, awaiting warmer weather.

By June and July, the use pattern changes to gun-an-go racing from spot to spot to tempt bass from their nests or hiding places. When the hot temperatures of summer come, the boat and motor are plunged into abusive saltwater to battle the current and sandbars on the Kennebec River for stripers. When the summer passes and the cold weather returns, the old boat serves as a shuttle for duck hunting and deer hunting, often breaking through ice to get to favorite spots in late November.

The life of an outboard motor is not an easy one, but with a few simple maintenance tips and a little tender care, you should be able to rely on one of your most important pieces of sporting equipment for seasons to come.

Perhaps the most important part of any outboard motor is the lower unit. This consists of the portion of the motor that is constantly underwater – the propeller, gears and lubricating fluid. Anytime lubricating oil comes near water, the chance for disaster is imminent.

While newer motors start with a factory watertight seal, they tend to leak as they age, allowing water to enter the lower unit, which destroys the protective properties of oil. Each fall when you put your motor away, it is recommended by almost all motor manufacturers that you drain and replace the lower-unit oil. If you use your outboard a lot, a mid-season change is good insurance against failure.

Changing the lower-unit fluid is no great task. If you have an owner’s manual, consult it for the best way to proceed. If you don’t have the manual, these instructions cover the majority of outboards in use today.

If you look at the lower unit, you will notice two screws on the same side of the unit, one above the other. The bottom one is usually marked “drain.” This is where the fluid will drain from. The top screw covers the air vent hole that allows fluid to be forced in and excess to flow out. Place a plastic pail below the drain hole and open it. Next, open the top screw, and the fluid should flow out.

If the fluid color ranges somewhere between amber and black, this is normal. If the fluid is milky or frothy, this indicates water has gotten into the unit and requires repair. Unless you are simply missing a rubber washer from the drain or vent screw, repairs to the integrity of the lower unit are best left to a qualified outboard mechanic.

Once the fluid has been drained, it is time to add fresh lubricant. Purchase a good quality marine lower-unit lube that covers the vast range of operating temperatures that your boat will endure. Many home mechanics use a pump, attached to the lube bottle, since it is easier to use than attempting to pour oil into the tiny filler hole. By screwing a nozzle into the lower drain hole and pumping gear-case lube in until it flows from the top vent hole, you know that the lower unit is full.

Next, replace the top vent screw which holds the lube in by suction. Remove the nozzle and replace the drain screw and you are in business. Use a rag to wipe the lower unit free of oil to help protect our lake and rivers.

The next area of simple outboard maintenance is the ignition system of the motor. While most modern outboards are too complicated for the backyard mechanic, replacing the spark plugs is a simple task that can save the day for a hard-to-start outboard. I prefer to replace my spark plugs at the start of each fishing season. While some may call this overkill, I never have to labor to start my 15-horsepower outboard, no matter what the temperature is. I also carry a spare set of spark plugs in a watertight case in my boat. You would be amazed how many times a fresh set of plugs revives a flooded motor. Be certain to get the exact plug that the manufacturer recommends and screw them in tightly, but not so tight that you strip the threads.

Another oft-forgotten part of your outboard maintenance schedule is the fuel system. Old fuel, dirty fuel and improper gas-to-oil ratios are the culprits of most failures. If you own a two-cycle outboard, be certain that you know the manufacturer’s recommended ratio. Years ago, almost every outboard ran on a 50 to 1 ratio. Now, many of the Japanese models use a leaner 100 to 1 ratio.

Using a gas/oil mixture without the proper amount of oil will spell disaster for your motor and your checkbook. Similarly, if you use old gasoline that has sat in a gas can all year long, you are asking for trouble. The narrow fuel passages and carburetor needles tend to become gummed up with a varnish-like substance when old gasoline is used. To prevent this from happening, use a fuel stabilizer in your gas cans when storing them and also run your motor dry of fuel at the end of the season.

My fishing partner unhooks his gas line at the boat ramp and runs his motor until it quits after each outing, assuring his fuel system is clean and dry.

Using dirty gasoline from unknown sources or using leftover gas from other engines also runs the risk of introducing foreign particles into your engine. It is smart to purchase a five-gallon gas can and label it “Outboard Gas – 100:1 Mix,” and fill it with top-grade gas and oil at the beginning of the season. When the tank in your boat runs dry, simply refill it with the proper mixture from a labeled gas can. When the fishing is good, I usually have to replenish my supply several times, but at least I know I am using fresh gas, and I never store any for the following season.

While these tips will prolong the life of your outboard motor, thoroughly reading and following the maintenance schedule is the only proper way to service it. If you don’t have one, write to the manufacture and purchase one, it is well worth the money.

By taking a few moments before, during and after your boating season and following a few simple procedures, you will not only save on future repair bills, you can rest assured that your outings on the water will be relatively trouble-free and enjoyable, so you can concentrate on the sport at hand.