Winterizing your inboard motor requires special attention. Every component, from the engine block to the accessories, needs to be thoroughly checked to avoid problems when the motor is put back into service. This procedure helps prevent damage caused by inactivity, particularly in damp, salty environments. Here are the essential steps for successfully winterizing your engine.
Engine block checks: Oil, spark plugs and fasteners
Engine oil and preheating
Checking oil levels is an essential first step. Before shutting down the engine for the winter, it is imperative to check and change the engine oil. An inactive engine containing used oil, often contaminated with combustion residues and water, risks internal damage during the resting period. Ideally, oil changes should be carried out when the engine is still warm, to allow the oil to drain more easily. Use a drain pump to extract the oil through the dipstick hole or directly through the drain plug, if accessible. Once the oil has been drained, replace the oil filter too, to ensure optimum filtration the next time the machine is used.
Glow plug inspection
Properly functioning glow plugs are crucial for easy starting. If engine starting is hesitant or chaotic, the glow plugs need to be tested. Each glow plug can be connected to a battery to assess how quickly it reaches the right temperature (bright red resistance in less than a few seconds). Spark plugs showing a delay in heating should be replaced, as they can cause starting difficulties. It is important to handle these parts with care to avoid burns during the test.
Motor mounting and vibration
Silent blocks, or rubber mounts, are essential for absorbing vibrations and holding the engine in place. While the engine is still warm, it is advisable to check that it is not moving abnormally. If excessive vibration or unexpected movement is detected, the engine mounts should be inspected. Faulty silent blocks can cause vibrations which, in the long term, affect the boat's entire structure.
Checking accessories: Battery and control systems
Battery charging circuit
A properly maintained engine won't start without a battery in good condition. Wintering is an opportunity to test the performance of the alternator and charging circuit. When the engine is running, the voltage delivered by the alternator should be between 13.8 and 14.2 volts for a 12-volt system. If it is lower, this may indicate a charging problem that could lead to battery failure during wintering. It is advisable to fully charge the battery before disconnecting it for the period of inactivity, or leaving it connected to an intelligent charger.
Control systems and linkages
On a boat, many mechanical controls (throttle, shuttle, steering wheel) are operated via cables or rods. To ensure smooth, friction-free operation, it's important to inspect and lubricate them regularly. Use a dedicated lubricant spray and apply it to the cable sheaths to prevent corrosion and facilitate cable sliding. If control movements are stiff or irregular, this may indicate a worn or damaged cable, which should be replaced before wintering.
Inverter and gearbox: Cooling and oil levels
Inverter cooling and control
The reverser and gearbox are critical components in a boat's drive train. Like the engine, they are often cooled by sea water. It's vital to check the condition of the oil in these devices before wintering. If the oil has bubbles or an abnormal texture (mayonnaise), this indicates the presence of water in the system, usually due to a faulty seal. Such a mixture can cause severe gear damage if the water is not removed quickly.
Flushing and filling the cooling system
A seawater-cooled motor should be flushed with fresh water before being left to stand. This removes salt that could cause corrosion on the internal surfaces of the motor and other components. Flushing is done by connecting the engine to a fresh water flushing system, or by replacing the water with an antifreeze coolant to protect internal parts from freezing during winter. This process is crucial for engines used in areas where winter temperatures drop below zero.
Electrical systems and cables: moisture prevention
Protecting the boat's electrical systems
The electrical components of an inboard motor are particularly vulnerable to moisture, which can lead to short circuits or oxidation. To prevent these risks, we recommend applying a water-repellent spray to electrical connections and battery terminals. This forms a barrier against humidity and salty air, reducing the risk of electrical failure. It is also advisable to check cables for signs of wear or contact with bilge water.
Lubrication of mechanical parts
All motor lubrication points, as well as moving parts such as control cables, must be lubricated before wintering. Use specific marine greases that resist corrosion caused by sea air. This step is often overlooked, but it will extend the life of mechanical components and ensure optimum operation when the boat is put back into service.
Preventing leaks and blockages: Water pump and belts
Seawater pump maintenance
The impeller of a seawater pump needs to be inspected regularly. Over time, it can wear and disintegrate, compromising water circulation and causing the motor to overheat. It is advisable to remove it, rinse it with fresh water and store it in a dry place for the winter. If it shows signs of wear, it should be replaced before the next season.
Checking and adjusting belts
The belts that drive the alternator and water pump must be properly tensioned for optimum performance. If they are too loose, they risk slipping and premature wear. During wintering, we recommend loosening the belts slightly, so as not to leave them under tension for long periods of inactivity, which could weaken them.
