Anyone who’s been around boating for a while remembers when many outboard powered boats had two engines. I’m not talking about a twin engine setup; I’m referring to one main power plant and a small kicker motor to the side, just in case. Back then, few offshore boats ventured out without a small back-up motor.
Today, outboard motor technology has advanced to the point where the kicker is largely a thing of the past. Motor manufacturers are standing behind their product longer and offering extended periods of time where no dealer scheduled maintenance is required, but don’t let that terminology lull you into complacency.
To ensure that reliability, you still must maintain your outboard and take steps to protect it from wear and corrosion. The time spent taking care of your motor may save a vacation, prevent a towing bill or circumvent an emergency.
Refer to your outboards owners’ manual for more detailed maintenance information on your particular engine. You won’t affect your engine’s warranty by doing the work yourself and all of the items listed in this article can be accomplished with simple hand tools. The time spent maintaining your outboard will not only protect your investment but will give you a better understanding of the operation and systems on the motor. This will give you a confidence boost when you’re miles away from the boat ramp and additional knowledge that won’t leave you at the mercy of a mechanic should other service be necessary.
Before You Use Your Boat
1. Remove the cowling and make a visual inspection looking for any oil leaks, loose wires or hoses. Be sure that the spark plug wires are securely seated onto the plugs.
2. If your engine is a four-stroke, check the oil level with the dipstick. If you have a two-stroke, check the oil level in the on-board or remote oil tanks.
3. If your powerhead has visible drive belts, check for cracks or splits in the belts.
4. Look at the hub of the propeller for any signs of fishing line caught around the prop shaft. Spin it by hand to make sure it turns freely.
5. Check the drain screws and prop seal on the lower unit for any signs of an oil leak.
6. Inspect the battery cable connections at the starter, engine block ground and the battery terminal posts to see if they are tight and free from corrosion that may prevent a good connection.
7. Look at the outside of the fuel lter/water separator canister filter. They are manufactured out of a thin metal and if installed in a bilge or wet area, they can rust out rapidly causing a fuel leak or allow air to be sucked into the canister which will impede fuel flow.
After Each Use
1. Flush your engine. Even if used in fresh water. All water contains contaminants that can build up in the cooling system. Either method of flushing by using the built-in flush attachment or the earmuff type on the lower unit, let the fresh water run for approximately 15 minutes to ensure a complete circulation.
2. Rinse the entire engine; trim unit and steeringsystem with fresh water. Wash down with a mild soap; a wash & wax combo car wash type soap works well. After the powerhead has cooled down it’s a good practice to rinse it down with fresh water as well, especially after use in saltwater, along with the underside of the engine cowling.
3. After the powerhead has dried, spray it with corrosion preventative, water displacing type lubricant. This would also be a good time to give the battery terminals and fuel filter canister a shot of the same spray.
1. If your engine is a four-stroke, change the engine oil and oil filter on a regularly scheduled basis. It’s not a hard job to do and you can do it yourself without voiding any warranties. Refer to your owner’s manual for intervals. Write the engine hours, month and year on the outside of the filter canister to help you remember when the next change is due.
2. Periodically pull your propeller and check for any fishing line that may be caught around the output shaft on the lower unit. Monofilament and especially braided lines will damage the shaft seal and cause a leak that could allow water to get into your lower unit or worst yet drain the lower unit of gear lube. Be sure to apply a liberal amount of marine grade grease to the prop shaft before reinstalling the prop. This will make it easier to remove in the future.
3. Change your fuel filter/water separator canister filter every fifty hours of operation. With the quality of today’s fuel, or lack of, filters can clog up easily. Like the oil filter, write the engine hours, month and year on the outside of the filter canister to help you remember when the next change is due.
4. The use of a fuel additive with every fill up is a good idea. Not just for boats that sit for an extended amount of time. Gasoline containing any amount of ethanol can break down quickly. The moisture-rich environment that boats are subjected to can introduce water into the fuel system even if you regularly use non-ethanol fuels.
5. Batteries should be checked for proper water levels and for corrosion buildup on the cable ends and terminals. Even if little or no corrosion is present, periodically remove the cables, brush the terminals and wire ends with a small wire brush. After reinstalling the cables, spray with a battery terminal protector, which will neutralize corrosion and leave a film barrier.
6. Loosen the upper vent screw and bottom filler screw on the lower unit and allow a small amount of gear lube to trickle out. See if any water is present in the gear lube, which would be milky in color, it’s the sign of a leaking seal. If it smells burnt, it’s time to be changed. Under normal use, change your lower unit gear lube every 100 hours of service. At this time you can also inspect the lower screw, it’s magnetic and will collect fine metallic dust, this is normal. Any larger chips could be signs of additional service needed.
7. Check the hydraulic fluid level in the power trim and tilt system. Any indication of the engine bleeding down while trimmed up or while underway could be a sign of low fluid or worn internal seals in the rams.
8. Anodes, commonly referred to as sacrificial zincs, are typically located on the lower unit and the bottom of the engine bracket. They protect the engine’s metal from corrosion and electrolysis. They should be replaced when, over time, they look like a piece of Swiss cheese or dissolve to 50% of their original size.
9. Water pump impellers supply cooling water to your engine. They can be damaged by sand and debris or if the engine is ever turned over while out of the water, even if just for a few seconds. Under normal conditions the internal rubber impeller can become deformed and lose some of its efficiency. A good rule of thumb is to replace the impeller once a year; it’s cheap insurance to keep your engine running cool. FS