2003 Mercury 40 HP ELPTO – 2S (M17256)

2003 Mercury 40 HP ELPTO – 2-Stroke (M17256) is a versatile and powerful outboard motor designed for small to medium-sized boats. It combines the reliability of Mercury’s engineering with the simplicity and performance of a 2-stroke engine, making it a popular choice for both recreational and utility purposes. Below is a detailed description:

Information

• Brand: Mercury
• Model Year: 2003
• Horsepower: 40 HP
• Engine Type: 2-Stroke
• Control Type: Remote with Power Trim and Electric Start
• Shaft Length: Available in Long (20 inches)
• Fuel Delivery: Carbureted
• Weight: Approximately 204 lbs

Key Features

• Electric Start (EL): Convenient starting with the turn of a key, eliminating manual pull-starting.
• Power Trim and Tilt (PT): Allows easy adjustment of the motor’s angle for optimal performance and shallow-water operation.
• Three-Cylinder Design: Ensures smooth operation with balanced power delivery.
• Corrosion Protection: Features Mercury’s proprietary anti-corrosion coatings, ideal for saltwater or freshwater environments.
• Durable Construction: Built with high-quality materials for long-lasting reliability and performance.

Fuel and Oil

• Fuel Type: Pre-mixed unleaded gasoline (minimum 87 octane) with 2-stroke oil.
• Fuel/Oil Mixture Ratio: Typically 50:1 (consult the owner’s manual for exact specifications).
• Fuel Tank: Compatible with an external fuel tank, often 6–12 gallons in capacity.

Performance and Applications

• Top Speed: Can achieve speeds of 25–35 mph, depending on boat size, weight, and load.

Applications:

• Fishing boats
• Pontoon boats
• Utility boats
• Small runabouts

Maintenance Tips

Fuel System Care

• Use fresh, ethanol-free fuel mixed with high-quality 2-stroke oil.
• Replace the fuel filter annually to prevent clogging and ensure clean fuel delivery.
• Inspect fuel lines and primer bulbs regularly for wear or cracks.

Spark Plug Maintenance

• Recommended Spark Plug: NGK BUHW-2 or equivalent.
• Inspect and clean spark plugs every 50 hours or seasonally.
• Replace spark plugs as needed and ensure the gap is set to 0.040 inches (verify with the owner’s manual).

Cooling System Maintenance

• Flush the motor with freshwater after each saltwater use to prevent corrosion buildup.
• Replace the water pump impeller every 2–3 years or if cooling efficiency decreases.

Lower Unit Maintenance

• Drain and replace gear oil annually or every 100 hours of operation.
• Inspect the propeller shaft for fishing line or debris and replace seals if necessary.

 Decarbonization

• Decarbonize the engine every 50–100 hours to remove deposits and maintain optimal performance.

Common Issues and Troubleshooting

Hard Starting

• Cause: Weak battery, stale fuel, or fouled spark plugs.
• Solution: Charge or replace the battery, use fresh fuel, and replace spark plugs as needed.

Overheating

• Cause: Clogged cooling water intake or worn impeller.
• Solution: Clear intake screens and replace the impeller.

Loss of Power

• Cause: Dirty carburetor, fouled spark plugs, or damaged propeller.
• Solution: Service the carburetor, replace spark plugs, and inspect the propeller.

Parts and Accessories

OEM Parts

• Mercury Dealers: Genuine parts are available through authorized Mercury dealers.
• Online Retailers:
  • MercuryMarine.com
  • Boats.net

Aftermarket Parts

• Sierra Marine: Compatible aftermarket parts such as filters, impellers, and carburetor kits.
• NGK Spark Plugs: High-quality replacement spark plugs for the engine.

Used Parts

• eBay: Refurbished or used parts for Mercury 40HP motors.
• Marine Salvage Yards: Reliable sources for older or hard-to-find parts.

Performance Enhancements

Propeller Optimization:

• Upgrade to a stainless steel or higher-quality propeller for better durability and performance.
• Choose a propeller pitch that matches your boating needs (e.g., higher pitch for speed, lower pitch for towing).

Fuel System Enhancements:

• Install a fuel stabilizer to prevent gum and varnish buildup.
• Use ethanol-free gasoline to minimize carburetor and fuel line issues.

Periodic Maintenance:

• Perform regular carburetor cleaning and tune-ups to maintain peak performance.
• Keep the engine well-lubricated and free of carbon deposits through regular decarbonization.

Additional Notes

• This motor is widely regarded for its reliability, making it a solid choice for both recreational boaters and professionals.
• Regular maintenance is essential to prolong the life of the motor and ensure smooth operation. 2003 Mercury 40 HP ELPTO – 2S (M17256)