Getting water out of a boat motor is a critical task to prevent severe damage like corrosion, rust, and hydrolock. The process varies depending on where the water has infiltrated the engine.
Understanding How Water Enters Your Boat Motor
Before addressing removal, it's helpful to understand how water can get into your motor in the first place. One common pathway is through the fuel system. As highlighted in discussions about water in outboard motors, water can be forced into the motor when its water trap fills up to a certain level, causing it to bypass the filter and get suctioned into the engine. This occurs when the water separator's capacity is exceeded, allowing water to bypass its intended filtration. Other sources include condensation in the fuel tank, contaminated fuel from a fuel pump, or even water getting past gaskets or seals into the engine's internal components.
Methods for Water Removal
Here's how to address water contamination in different parts of your boat motor:
1. From the Fuel System
Water in the fuel system is a common issue, often due to condensation or contaminated fuel.
- Drain the Fuel/Water Separator:
- Location: Most outboard and inboard marine engines have a fuel/water separator filter, usually a clear bowl or a separate filter housing.
- Procedure:
- Locate the filter, which often has a drain valve or plug at the bottom.
- Place a suitable container beneath the filter to catch the drained fuel and water.
- Open the drain valve or loosen the plug to allow the water (which is heavier than fuel) to drain out first.
- Continue draining until clear fuel begins to flow, then close the valve/plug.
- Tip: If a significant amount of water drains, or if water continues to appear, the main fuel tank might need draining and cleaning.
- Clean or Drain the Fuel Tank:
- If the fuel/water separator repeatedly fills with water, the main fuel tank is likely contaminated.
- Procedure: The safest and most effective way is to pump out all fuel from the tank into approved containers. Inspect the tank for sludge or debris. Professional cleaning might be necessary for heavily contaminated tanks.
- Replace Fuel Filters:
- After draining water, it's highly recommended to replace all inline and engine-mounted fuel filters. Water can degrade filter media and lead to blockages.
2. From Engine Cylinders (Addressing Hydrolock)
Hydrolock occurs when water enters an engine cylinder, as water is incompressible. Attempting to start an engine with hydrolock can cause severe damage, such as bent connecting rods or a cracked engine block.
- Symptoms: Engine won't crank or cranks slowly with a distinct "clunk" sound.
- Procedure:
- Disconnect Battery: For safety, disconnect the boat's battery to prevent accidental cranking.
- Remove Spark Plugs: Carefully remove all spark plugs from the engine's cylinders.
- Crank the Engine: With the spark plugs removed, water trapped in the cylinders can be expelled.
- Outboard Motors: Manually turn the propeller by hand (with the gear in neutral) or gently crank the engine using the starter (in short bursts of 1-2 seconds) to push water out of the spark plug holes.
- Inboard Motors: Use a wrench on the crankshaft pulley to slowly turn the engine over, or briefly crank with the starter.
- Dry and Inspect:
- After expelling water, spray a fogging oil or a light lubricant into the cylinders to displace any remaining moisture and prevent rust.
- Crank the engine a few more times to distribute the oil.
- Clean and dry the spark plugs or replace them if they appear fouled or damaged.
- Change Engine Oil and Filter: Water can seep past piston rings into the crankcase, contaminating the engine oil. Always perform an oil and oil filter change after a hydrolock incident.
3. From Engine Oil
If water enters the engine's crankcase, it mixes with the oil, forming a milky or frothy emulsion. This significantly reduces the oil's lubricating properties and can lead to rapid wear and engine failure.
- Symptoms: Engine oil on the dipstick appears milky, frothy, or cloudy.
- Procedure:
- Drain Contaminated Oil: Completely drain the old, contaminated engine oil.
- Replace Oil Filter: Always install a new oil filter.
- Refill with Fresh Oil: Add the correct type and amount of fresh engine oil.
- Run Briefly: Run the engine for a short period (5-10 minutes) to circulate the new oil.
- Repeat Oil Change: Drain this "flush" oil (which might still show signs of contamination) and replace the oil filter again. Refill with fresh oil. This double-change method helps ensure all water is removed from the system.
- Identify Entry Point: If water repeatedly contaminates the oil, there might be a leak in the cylinder head gasket, engine block, or a damaged heat exchanger (for closed cooling systems). Professional diagnosis is recommended.
Prevention Strategies
Preventing water from entering your boat motor is always better than removing it:
- Regular Fuel/Water Separator Maintenance: Regularly check and drain your fuel/water separator. Replace the filter cartridge according to manufacturer recommendations.
- Source Clean Fuel: Purchase fuel from reputable marinas or stations with high turnover to minimize the risk of contaminated fuel.
- Use Fuel Stabilizers and Additives: Certain fuel additives can help emulsify small amounts of water or prevent its buildup.
- Store Fuel Properly: If storing fuel in separate containers, ensure they are sealed and stored in a cool, dry place.
- Inspect Bilge and Hoses: Ensure the bilge is dry and all hoses, clamps, and connections are secure to prevent water intrusion.
By diligently following these steps and maintaining your boat motor, you can effectively remove water and protect your engine from costly damage.
