Completing navigation is not just the moment you pull the boat ashore, but the beginning of a critical process that determines the life of your engine. Many owners make the mistake of believing that a four-stroke motor is easy enough to plug and remove into the garage, but without proper preparation, internal mechanisms can suffer from corrosion and oxidation during downtime.
Competent preservation of the four-stroke outboard motor allows you to protect expensive components from the aggressive effects of moisture, fuel residues and acidic environment formed in the crankcase. Neglecting these procedures often leads to the fact that in the spring instead of the joy of the first start of the owner is waiting for a complex and costly repair.
In this article, we will analyze all the stages of preparing the power unit for winter storage, paying special attention to the specific requirements of four-stroke engines, which differ from their two-stroke counterparts in the design of the lubrication and gas distribution system.
Preparation and external inspection before conservation
The first step is always to thoroughly wash and visually inspect the unit after the last launching, to wash off the salt deposits if operated in seawater, or just mud and river silt using fresh water and a soft brush. Pay special attention to lower unit, because that is where most often there are hidden damage that is better to repair before winter.
During the inspection, check the condition of the lower unit bolts, the motor attachment to the transom and the integrity of the lower unit pipe. Any scratches on the body of the lower unit should be painted to prevent the corrosion of the metal in the cold season, and inspect the fuel hoses for cracks and scuffs.
⚠️ Warning: Never wash a hot engine with cold water – a sharp temperature drop can lead to deformation of the cylinder head or the formation of microcracks in the metal.
After washing, let the motor dry completely or blow out hard-to-reach places with compressed air. Humidity is the main enemy of electrics and metal surfaces during long-term storage, so quality drying is a must. Make sure that the drainage holes in lower unit are not clogged.
Fuel system maintenance
Modern gasoline fuels have a limited shelf life and are prone to decay, forming resinous deposits that clog the carburetor or fuel injectors. For four-stroke engines that are sensitive to the quality of the mixture, this is especially true. There are two main approaches: full production of fuel or its stabilization.
If you choose a stabilization method, add a special stabilizer preservative to the tank in the proportion specified by the manufacturer, and let the engine run for 5-10 minutes idling, which is necessary for the processed fuel to pass through the entire system, including the fuel pump and the fuel pump. carburetor It's not recommended to leave gasoline in a tank without a stabilizer for the winter.
The alternative is to completely drain the fuel from the tank, the fuel hoses and the float chamber, so shut off the fuel crane, disconnect the hose and blow the system with compressed air, and injector systems may require the fuel pump to be turned off and the engine to shut down completely.
- 🛢️ Add the fuel stabilizer to the tank and let the motor run for 10 minutes to circulate the mixture.
- 💧 Pour the sludge from the fuel filter separator and check for water.
- 🔌 Disconnect the fuel hose and shut the holes of the tank and motor.
- 🧹 Wipe the fuel tank outside and check the vent of the cover.
⚠️ Warning: When working with fuel and cleaning the carburetor, observe fire safety measures and do not allow gasoline to hit rubber seals, as this can cause them to swell.
Use only stabilizers that are compatible with your fuel system materials (ethanol-containing fuels require special additives).
Replacement of engine oil and filter
One of the most important procedures in preparation for winter is to change the oil in the crankcase of a four-stroke engine, in the process of working in the oil accumulates combustion products, metal shavings and acid, which, with prolonged downtime, begins to actively corrode bearings and rubbing vapors from the inside.
Change the oil while the engine is still warm (but not hot) to ensure maximum drainage of the workout along with suspended particles. After draining the old oil, be sure to replace the oil filter if your design is Yamaha, Honda or Suzuki Pour the new oil to the level indicated on the probe.
After changing the oil and filter, start the engine for 2-3 minutes idling, so that fresh oil fills the oil filter and lubricates all the nodes, creating a protective film for the winter. Check for no leaks from the plum plug and filter.
☑️ Oil replacement
Also, be sure to check the oil level in the gearbox. Although it is changed less often, usually once a season or by motor clock, visual color and consistency control is mandatory. If the oil in the gearbox is "coffee with milk", then the leakage of the coils is broken and water enters the gearbox.
Conservation of cooling and lower unit systems
The four-stroke cooling system is full of water channels that may contain water residues after the season. When frozen, water expands and can split the cylinder block or the block head, so removing it is critical. Four-strokes have a more complex cooling shirt system than two-strokes.
Remove the thermostat (if the design allows easy access) or simply blow the system thoroughly with compressed air through the inlet of the water pump. Some manufacturers recommend pumping through the system anti-corrosion compound or antifreeze solution, specially designed for the preservation of outboard motors.
The lower unit lubricant requires special attention, removing the lower unit bolt, cleaning the thread and lubricating it with a special lubricant that is resistant to washing, and lubricating the hinges of the tilt and turn of the motor, the gas cable and gear shifts.
| Node. | Type of lubricant | Frequency | Features |
|---|---|---|---|
| Tilt hinges | Lithium lubricant | Every season. | Plenty, until fresh lubrication appears |
| Control cables | Spray lubricant | Every season. | Remove the caps, splash in. |
| lower unit's schlitz | Graphite Grease | When the screw is removed | Thin layer, no bigotry |
| Bolt-carving | Copper lubrication | Every season. | Protection against quilting |
Complete removal of water from the cooling system is the only guarantee that the engine block will not disturb in the first severe frost.
Protection of cylinders and electrical parts
To preserve the cylinder-piston group (CPG), an oil mist must be created inside the combustion chambers, which will cover the cylinder walls, rings and valves with a protective layer. In four-stroke engines, cylinders are accessed through spark plugs.
Unscrew all the spark plugs and pour about 10-15 ml of engine oil into each cylinder. Then make a few turns with the starter (by first turning off the ignition coils or the fuel pump fuse so that the engine does not start), spreading the oil over the walls. Roll the candles back or install new ones if the old ones have run out of life.
⚠️ Warning: When scrolling the engine with the removed candles be careful - oil can spill out of the candle wells, so cover the holes with rags.
The electrical part also requires protection. Remove the battery, fully charge it and store it in a warm room, periodically recharge. Battery terminals and electric motor connectors treat with a moisture dislodging spray (WD-40 or analog) and conserve with lithium lubricant to prevent contact oxidation.
Do I need to take the motor off the boat?
Whether you take the engine off or not depends on the storage conditions. If the boat is left on the water or in a damp hangar, it is better to remove the engine and store it vertically in a dry room. If the boat is stored in a trailer in a dry garage, you can leave the engine, but you must be in an upright position so that water does not enter the exhaust system.
Proper storage and position of the motor
The four-stroke outboard motor should be stored strictly in the vertical position, this requirement is due to the design of the lubrication system and the possibility of oil draining into the combustion chamber or, conversely, draining important components. Horizontal storage is allowed only on special stands provided by the manufacturer.
The storage room should be dry, well ventilated and protected from direct sunlight, which destroys rubber parts and fades plastic. If the motor is stored outside, use a special breathable case that protects from precipitation, but allows moisture to escape from the inside.
Do not cover the engine tightly with plastic film without air, this will create a greenhouse effect and accelerate the corrosion of metal parts, it is better to use fabric covers or leave gaps for ventilation in the bottom of the casing.
Frequently Asked Questions (FAQ)
Should I start the engine in winter during storage?
No, running a canned engine in winter is not recommended unnecessarily, and working briefly without warming up to operating temperature will cause moisture to condense in the oil and exhaust system, which will only harm the engine.
Can I keep the engine on my side?
Four-stroke engines should not be stored on the side unless they are mounted on a special stand. In the usual position, oil flows into the head of the block or cylinders, which can lead to hydraulic shock at the next start or oil starvation of the nodes.
How often should the battery be recharged during storage?
Lead-acid batteries require recharging every 1-2 months depending on the storage temperature. Lithium batteries hold the charge longer, but controlling the voltage once every 3 months will also not be superfluous.
What to do if an emulsion appears in the oil?
The presence of an emulsion (“coffee with milk”) indicates the ingress of water into the oil through the oil cods or gasket of the GBC. It is impossible to operate such a motor - diagnostics, replacement of omentation/pads and a complete rinse of the lubrication system are required.