Suzuki 20 Hp Outboard Problems

The Suzuki 20 hp outboard engine is a popular choice for small boats, fishing vessels, and recreational users due to its fuel efficiency, reliability, and ease of use. However, like any mechanical device, it's not immune to problems. Knowing common issues and how to address them can save you time, money, and frustration, ensuring you spend more time on the water and less time troubleshooting. Addressing these potential issues proactively is key to keeping your Suzuki 20 hp running smoothly for years to come.

Starting Troubles: Why Won't My Suzuki Fire Up?

One of the most common complaints with any outboard engine, including the Suzuki 20 hp, revolves around starting difficulties. This can be especially frustrating when you're eager to get out on the water. Let's explore some of the usual suspects:

Fuel Issues: This is often the first place to look.
- Old or Stale Fuel: Gasoline degrades over time, especially when mixed with ethanol. Always use fresh fuel, preferably with a fuel stabilizer, and avoid storing fuel for extended periods. Drain the fuel tank and lines if the engine hasn't been used for several months.
- Clogged Fuel Filter: The fuel filter prevents debris from entering the engine. A clogged filter restricts fuel flow. Inspect and replace the fuel filter regularly, typically every 100 hours of use or annually.
- Fuel Line Problems: Check for kinks, cracks, or leaks in the fuel lines. Ensure the fuel line is properly connected to the engine and the fuel tank.
- Fuel Pump Issues: The fuel pump delivers fuel to the carburetor or fuel injectors. A faulty fuel pump can prevent the engine from starting. Listen for the fuel pump priming sound when you turn the key. If you don't hear it, the pump may be failing.
- Carburetor Problems (Older Models): If your Suzuki 20 hp has a carburetor (older models), it can become clogged with varnish or debris. Consider cleaning the carburetor using a carburetor cleaner or having it professionally serviced.
Spark Issues: A healthy spark is essential for ignition.
- Faulty Spark Plugs: Inspect the spark plugs for fouling, cracks, or wear. Replace spark plugs according to the manufacturer's recommendations. Ensure the spark plug gap is correct.
- Ignition Coil Problems: The ignition coil provides the high voltage needed to create a spark. A failing coil can result in a weak or nonexistent spark. Use a spark tester to check for spark at each cylinder.
- Kill Switch Activation: This might sound obvious, but it's a common oversight. Ensure the kill switch lanyard is properly attached. A disconnected kill switch will prevent the engine from starting.
Battery Problems (Electric Start Models):
- Weak or Dead Battery: A weak battery may not provide enough power to turn the engine over. Check the battery voltage and charge it if necessary. Consider replacing the battery if it's old or unable to hold a charge.
- Loose Battery Connections: Ensure the battery terminals are clean and securely connected.

Overheating: When Your Suzuki Runs Too Hot

Overheating can cause serious damage to your Suzuki 20 hp outboard. It's crucial to address overheating issues promptly to prevent costly repairs.

Water Pump Impeller Failure: The water pump impeller circulates cooling water through the engine. A worn or damaged impeller is a common cause of overheating. Replace the water pump impeller every 100-200 hours of use, or annually, especially if you operate in sandy or silty water.
Clogged Cooling Passages: Debris, salt, or corrosion can block the cooling passages within the engine. Flush the cooling system regularly with fresh water, especially after use in saltwater. Consider using a descaling solution to remove stubborn deposits.
Thermostat Issues: The thermostat regulates the engine temperature. A faulty thermostat can prevent the engine from cooling properly. Test the thermostat by placing it in hot water. It should open fully. Replace the thermostat if it's not functioning correctly.
Low Water Level: Ensure the engine is submerged to the proper level for cooling.
Obstruction of Water Intake: Check for weeds, plastic bags, or other debris blocking the water intake on the lower unit.

Performance Problems: Loss of Power and Rough Running

A noticeable decrease in performance or rough running can indicate several underlying issues.

Propeller Damage: A damaged propeller can reduce efficiency and performance. Inspect the propeller for dents, cracks, or bends. Repair or replace the propeller as needed.
Incorrect Propeller Size: Using the wrong propeller size can affect performance. Consult your owner's manual or a marine mechanic to determine the correct propeller size for your boat and operating conditions.
Fouled Spark Plugs: As mentioned earlier, fouled spark plugs can cause misfires and reduce power. Inspect and replace spark plugs regularly.
Carburetor Issues (Older Models): A dirty or improperly adjusted carburetor can lead to poor performance. Clean the carburetor and adjust the idle mixture according to the manufacturer's specifications.
Compression Problems: Low compression in one or more cylinders can indicate worn piston rings or valve issues. Perform a compression test to assess the condition of the engine's cylinders.
Ignition Timing Issues: Incorrect ignition timing can affect performance and fuel efficiency. Check and adjust the ignition timing according to the manufacturer's specifications.

Unusual Noises: What's That Sound?

Unusual noises coming from your Suzuki 20 hp should never be ignored. They often signal a developing problem that needs attention.

Knocking: A knocking sound can indicate serious engine damage, such as worn bearings or connecting rods. Stop using the engine immediately and have it inspected by a qualified marine mechanic.
Squealing: A squealing sound often indicates a worn belt or a dry bearing. Inspect the belts and pulleys for wear and tear. Lubricate bearings as needed.
Grinding: A grinding sound can indicate a problem with the lower unit gears or bearings. Have the lower unit inspected and serviced by a qualified marine mechanic.
Clicking: A clicking sound when starting the engine can indicate a weak battery or a faulty starter motor. Check the battery voltage and connections. Inspect the starter motor for damage.

Lower Unit Issues: Keeping the Drive System Healthy

The lower unit is a critical component of your outboard, responsible for transmitting power to the propeller. Maintaining it properly is crucial.

Water in the Gear Oil: Water in the gear oil can cause corrosion and damage to the gears and bearings. Check the gear oil regularly for signs of water contamination. If water is present, drain the gear oil, replace the seals, and refill with fresh gear oil.
Damaged Propeller Shaft Seals: Damaged propeller shaft seals can allow water to enter the lower unit. Inspect the seals for damage and replace them as needed.
Worn or Damaged Gears: Worn or damaged gears can cause noise and reduced performance. Have the lower unit inspected and serviced by a qualified marine mechanic if you suspect gear problems.

Preventative Maintenance: The Key to Longevity

The best way to avoid problems with your Suzuki 20 hp outboard is to perform regular preventative maintenance.

Follow the Manufacturer's Recommendations: Consult your owner's manual for the recommended maintenance schedule.
Change the Oil Regularly: Change the engine oil and filter according to the manufacturer's recommendations.
Grease Fittings: Grease all grease fittings regularly to lubricate moving parts.
Inspect and Clean the Cooling System: Flush the cooling system regularly to remove debris and prevent overheating.
Check and Adjust Cables: Check and adjust the throttle and shift cables to ensure proper operation.
Store Your Engine Properly: When storing your engine for extended periods, follow the manufacturer's recommendations for winterization.

Frequently Asked Questions

Why is my Suzuki 20 hp hard to start when cold? A cold engine often requires a richer fuel mixture. Ensure the choke is engaged, and the fuel is fresh.
How often should I change the gear oil in my lower unit? It's generally recommended to change the gear oil every 100 hours of use or annually, whichever comes first.
What type of fuel should I use in my Suzuki 20 hp? Use fresh, unleaded gasoline with an octane rating of 87 or higher. Consider using a fuel stabilizer, especially if the engine will be stored for extended periods.
How do I flush the cooling system on my Suzuki 20 hp? Use a flushing attachment to connect a garden hose to the engine's cooling water inlet. Run the engine briefly while flushing with fresh water.
Where can I find the serial number on my Suzuki 20 hp? The serial number is typically located on a metal plate on the engine bracket.

Conclusion

Addressing potential problems with your Suzuki 20 hp outboard proactively, along with consistent preventative maintenance, will ensure you enjoy reliable performance and a long lifespan for your engine. Don't hesitate to consult a qualified marine mechanic for any issues you can't resolve yourself.