When To Change Outboard Fuel Lines: Maintenance Guide

The frequency with which fuel lines in outboard boats should be replaced is a topic of much discussion among boat owners. While some suggest that fuel lines should be replaced every 5 years, others recommend doing so only when signs of deterioration appear, such as cracks or a loss of flexibility in the hose. Ethanol-containing gasoline, which can eat away at fuel lines from the inside, is a significant factor in this decision. To prevent issues, it is recommended to use fuel lines that are resistant to ethanol or to replace the lines with automotive fuel hoses, which are more durable but lack UV protection.

Fuel line replacement frequency: every 3-5 years, or 10 years maximum

Fuel lines are a crucial component of any boat, ensuring the engine receives the fuel it needs to run. However, they don't last forever, and replacing them at the right time is essential to prevent problems and ensure the engine's longevity. So, how often should you change your fuel lines?

The consensus among boaters and experts is that fuel line replacement should occur every 3-5 years. This recommendation is supported by the observation that fuel hoses are typically warranted for 3-5 years. While some boats may go longer without issues, it is generally advisable to replace them within this timeframe to avoid potential problems.

However, there are some signs that your fuel lines may need to be replaced sooner. One key indicator is the condition of the hose. If the fuel hose loses its softness and flexibility, it's time to replace it. Additionally, if there are any signs of cracking or splitting, it is crucial to replace the fuel lines immediately to prevent leaks and potential safety hazards.

It is worth noting that fuel lines exposed to sunlight or UV rays may need to be replaced more frequently, as they tend to deteriorate faster. As a result, it is recommended to inspect fuel lines annually and replace them no later than 10 years to ensure safety and maintain engine performance.

When replacing fuel lines, it is essential to use the correct type of hose for your specific application. For example, A1-rated hoses are typically used for feeding fuel from the tank to the engine and are designed to have fuel in them at all times. On the other hand, A2-rated hoses are used for the fuel tank vent and are not intended to have fuel sitting in them.

In addition to selecting the right type of hose, it is crucial to use the appropriate size fuel line for your outboard engine. For instance, a 5/16" fuel line is suitable for engines up to 115 HP, while a larger 3/8" fuel line is required for engines above that horsepower. Using the correct size ensures the engine receives adequate fuel and prevents strain on the fuel pumps.

In conclusion, fuel line replacement is an important aspect of boat maintenance. By replacing your fuel lines every 3-5 years or at the first sign of deterioration, you can help ensure safe and reliable operation of your boat's engine. Remember to use the correct type and size of fuel line for your specific application and inspect your fuel lines regularly to identify any potential issues.

Ethanol-resistant fuel lines: post-2008 lines are more resistant

Ethanol-resistant fuel lines are essential for protecting your boat's engine. The ethanol in fuel can eat away at the inside of older fuel lines, causing varnish to clog injectors and the line itself to collapse. This can lead to fuel line failure and engine issues, including lean conditions that can cause the engine to stall.

To combat this, it is recommended to replace your fuel lines with newer, ethanol-resistant lines if your boat is a 2007 model or older. One user on The Hull Truth forum reported that their mechanic told them to replace their lines if their boat was pre-2008. The user also mentioned that ethanol had permeated their silicone fuel line, causing it to fall apart in their hand. Another user on iboats reported that their 1996 original fuel lines were showing signs of permeation and that the new regulation A1-15 lines are supposed to resist ethanol better.

Goodyear manufactures a rubber fuel hose with a blue liner that is resistant to ethanol, although it may not be USCG approved. Sierra also offers grey below-deck fuel line options that are ethanol-resistant, but these are also not USCG approved for inboards and I/Os. MPI is another brand that manufactures ethanol-resistant fuel lines for inboard and I/O boat applications.

When replacing your fuel lines, it is important to use Marine Specified replacement fuel lines. It is also recommended to install an inline filter to save yourself from potential carb problems. Additionally, it is worth noting that fuel lines are typically warranted for 3-5 years, and their service life is estimated at around 10 years, less if exposed to sunlight.

Fuel line sizing: 5/16 for _115 HP engines; 3/8 for >115 HP engines.

Fuel lines should be regularly inspected for cracks, leaks, and other signs of damage. It is recommended that fuel lines are replaced every 3-5 years, or every 10 years at most. However, this depends on several factors, including the age of the boat, the type of fuel, and the frequency of use. For example, ethanol-based fuels can eat away at the inside of the lines, causing varnish to clog injectors. This is a common issue in boats older than the 2008 model, so fuel lines should be replaced with more ethanol-resistant lines.

Fuel lines should also be replaced if the boat has been stored in certain conditions, such as in an old greenhouse, as this can cause the lines to deteriorate. Additionally, it is important to use the correct fuel line size for your engine. For outboard engines, a 5/16" fuel line is suitable for smaller engines up to 115 HP. For engines above 115 HP, a larger 3/8" fuel line is required. This is because larger engines demand more fuel to run at higher RPMs, and using a smaller fuel line can cause the engine to run lean, leading to strain on the fuel pumps and potential damage to the engine.

It is also worth noting that there are different types of fuel hoses for different applications. Hoses with US Coast Guard ratings A1, A2, B1, and B2 are designed for use below or above the deck of the boat, with A1 and B1 being used for feeding fuel to the engine, and A2 and B2 for vent hoses.

Fuel line types: A1, A2, B1, B2 (fire-resistant/non-resistant, below/above deck)

The US Coast Guard has classified fuel lines into four types: A1, A2, B1, and B2. These classifications are based on the location of the fuel line (above or below the deck) and the fire-resistant properties of the hose.

A1 hoses are used for feeding fuel from the boat's fuel tank to the fuel filter bracket or the engine. They are rated for below-deck use and have a fire-resistant covering on the outside. A2 hoses are used for the fuel tank vent hose below the deck. They are not designed to have fuel sitting in them but do have a fire-resistant covering.

B1 hoses are similar to A1 hoses but are used for fuel lines that are above the deck or not enclosed. They do not have the same fire-resistant covering as A1 hoses. B2 hoses are used for the fuel tank vent hose above the deck or in unenclosed spaces. They are similar to A2 hoses but lack the fire-resistant covering.

It is important to use the correct type of fuel hose for your specific application to ensure safety and compliance with regulations. A1 hoses, for example, are required for high-pressure fuel lines below the deck, as they offer the highest fire resistance and the least amount of permeability.

When replacing fuel lines, it is recommended to use the newer A1-15 or B1-15 hoses, which have a new rating for ultra-low permeability and are more resistant to ethanol-blended fuels. These hoses are now required by EPA regulations and will help prevent issues caused by ethanol eating away at the inside of the fuel lines.

In terms of how often to replace fuel lines, it is generally recommended to do so every 3-5 years, or every 10 years at most. However, it is important to regularly inspect the fuel lines for any signs of deterioration or cracking, as fuel lines can deteriorate from the inside out due to exposure to sunlight and ozone. If there is any residue or permeation, it may be time to replace the lines, especially if your boat is over 15 years old.

Fuel line maintenance: check for cracks, squishiness, lumps, and residue

Fuel line maintenance is an important aspect of keeping your boat in good condition and ensuring its engine's optimal performance. Here are some detailed instructions for checking your fuel lines for cracks, squishiness, lumps, and residue:

Checking for Cracks and Wear:

Visually inspect the entire length of the fuel lines, paying close attention to connections, joints, and fittings. Look for any signs of cracking, wear, or damage. If you notice any cracks, no matter how small, it's important to replace the fuel lines as soon as possible. Even minor cracks can lead to fuel leaks, which pose safety hazards.

Checking for Squishiness and Lumps:

Feel the fuel lines to assess their texture and condition. If the lines feel squishy or soft, it's an indication that they need to be replaced. Also, look for any lumps or uneven areas on the surface of the lines, as this may indicate degradation or the presence of residue.

Checking for Residue:

Disconnect the fuel lines at both ends and inspect the inside. Use a flashlight to look for any signs of residue, varnish, or debris buildup. If you notice any residue, it's important to clean or replace the lines to prevent blockages and ensure uninterrupted fuel flow. Additionally, check your fuel filters regularly and replace them according to the manufacturer's recommended maintenance schedule.

Other Maintenance Tips:

• To prevent fuel line issues, it's recommended to replace your fuel lines if your boat is older than a 2007 model, as ethanol in the fuel can eat away at the lines.
• Consider installing an inline filter to help catch debris and reduce the risk of carb problems.
• Regularly inspect your fuel lines for any signs of damage or leaks, especially if your boat is exposed to harsh environments or sunlight, as this can accelerate deterioration.
• Keep an eye on fuel consumption and monitor your fuel usage for any unexplained increases, which could indicate a leaking fuel line.

Frequently asked questions