Changing Fuel Filter: Mercury 250 Pro Xs Guide

Changing the fuel filter on a Mercury 250 Pro XS is a maintenance task that boat owners may need to perform from time to time. The process involves accessing the fuel filter, which is typically located near the engine, and replacing it with a new one. Some sources recommend using a specific type of grease on the hose fittings and the base of the filter, such as 2-4-C grease or a light coating of clean oil, to ensure a proper seal and prevent leaks. It is also important to consider the micron filtration of the replacement filter to ensure it effectively removes particulates from the fuel. Additionally, some boat owners choose to install an additional water separator filter before the engine to prevent water ingress, which can cause significant damage if it reaches the engine.

The type of grease to use on the hose fittings and the base of the filter

When changing the fuel filter on a Mercury 250 Pro XS, it is important to use the right type of grease on the hose fittings and the base of the filter. Mercury recommends applying a light coating of 2-4-C grease to these areas. This is a premium marine grease specifically designed for outboard motors. It is a lithium-based, NLGI 2 grease that is fuel-soluble and won't break down when mixed with water. It offers excellent resistance to oxidation and degradation and can withstand high temperatures and friction.

If you don't have the Mercury 2-4-C grease, it is important to use a suitable replacement. Some people suggest using a light coating of clean oil, while others recommend a small amount of 2-stroke oil. It is important to avoid using white lithium grease as it is not compatible with the fuel filter.

To apply the grease, first, wipe off any old grease, dirt, or debris from the hose fittings and the base of the filter. Then, use a grease gun or your finger to apply a light coating of grease to these areas. Make sure to leave a bit of grease on top of the grease fittings to prevent rust and debris from accumulating.

In addition to the fuel filter, there are several other grease points on a Mercury outboard that should be lubricated at regular service intervals. These include the grease fittings or zerks, moving components, and pivot locations. The propeller shaft, throttle cables, shift cables, cowling latch, and transom clamp screws should also be greased.

The best place to buy a new fuel filter

When it comes to purchasing a new fuel filter for your Mercury 250 Pro XS, there are a few options available to you. It is important to ensure that you are buying the correct part for your engine, so it is recommended to use the serial number to identify the right fuel filter. Here is a direct and detailed guide on the best places to buy a new fuel filter:

Firstly, it is suggested that you visit your nearest Mercury Dealer. They are likely to have the correct fuel filter in stock and can provide expert advice on the specific part required for your engine. This option ensures that you are buying a genuine Mercury product and avoids the risk of purchasing cheap knock-offs that may not be compatible or of the same quality.

Alternatively, you can opt for online shopping. Amazon offers fuel filters compatible with the Mercury 250 Pro XS engine. For example, the Caltric Fuel Filter is specifically designed for the Mercury Marine 250 Pro XS DFI 250Hp from 2006 to 2010. It is important to carefully check the product description and part numbers to ensure compatibility with your engine. Amazon also offers the Quicksilver by Mercury Marine Fuel Filter Element, which is compatible with select Mercury and Mariner Outboards and MerCruiser Sterndrive Engines.

Another online option is to refer to the official Mercury Marine website. By entering your serial number, you can identify the correct part number for your specific Mercury 250 Pro XS model. This ensures that you purchase the right fuel filter for your engine.

Finally, forums and groups dedicated to Mercury boats, such as Bass Cat Boats, can be a great resource. Here, owners share their experiences and recommendations on where to buy parts, including fuel filters. It is a community-driven space where you can seek advice and learn from others' experiences.

In summary, while Mercury Dealers provide expert advice and genuine products, online options like Amazon and the Mercury Marine website offer convenience and a wide range of compatible fuel filters for your Mercury 250 Pro XS engine. Forums and groups are also valuable resources for seeking recommendations and advice from fellow boat owners.

Whether to use a filter wrench and how to get one

When changing the fuel filter on a Mercury 250 Pro XS, it is recommended to use a filter wrench for ease of removal and installation. This tool can be purchased from a Mercury dealer or on Amazon for less than $10.

The filter wrench is designed to help loosen and tighten the fuel filter, making it easier to remove and install. It is a specialised tool that fits the unique shape of the fuel filter, providing a secure grip and reducing the risk of slipping or damaging the filter during the process.

To use the filter wrench effectively, locate the fuel filter on your Mercury 250 Pro XS. It is usually found near the engine, often with a castle-like fixture. Once located, position the filter wrench securely around the fuel filter. Apply firm but controlled force to loosen the filter in a counter-clockwise direction. After removing the old filter, you can then use the wrench to tighten the new filter by turning it clockwise.

If you choose to purchase the filter wrench from a Mercury dealer, you can ask for their recommendation on the best wrench for your specific model. They will likely have a range of options designed specifically for Mercury outboards, ensuring a perfect fit. Alternatively, Amazon offers a convenient option for purchasing the tool at a reasonable price, as mentioned by a user who has successfully changed their fuel filter.

In summary, using a filter wrench is highly recommended when changing the fuel filter on a Mercury 250 Pro XS. It simplifies the process, reduces the risk of damage, and ensures a secure fit for the new filter. With its low cost and specialised design, the filter wrench is a worthwhile investment for any boat owner performing maintenance on their Mercury outboard.

How to drain the tank and clean it

To drain the tank, you will need to remove the fuel filter. This can be done by using a screwdriver or a filter wrench, which can be purchased cheaply from Amazon or a Mercury dealer. Once the filter is removed, you can start to drain the tank.

Use a mighty vac brake bleeder to vacuum off all the fuel in the tank. This will create a suction that will help to remove the fuel quickly and efficiently. It is important to be thorough during this step to ensure that the tank is completely drained.

After the tank is drained, it's time to clean it. Start by inspecting the water sensor and ensuring that it is free of any gunk or debris. You can use brake parts cleaner to gently clean the sensor if needed. It is important to ensure that the sensor is functioning properly to detect any water in the fuel, as this can cause damage to the engine.

Next, you can move on to cleaning the inside of the tank. Again, brake parts cleaner can be used to remove any built-up residue or contaminants. Be sure to wear appropriate protective gear, such as gloves and eye protection, during this process. Use a clean, dry cloth to wipe down the inside of the tank, ensuring that it is free of any cleaning solution residue.

Once the tank is thoroughly cleaned, it is important to let it dry completely before reinstalling the fuel filter and adding new fuel. This process will help ensure that your Mercury 250 Pro XS fuel system is clean and well-maintained, which can help extend the life of your engine.

The importance of installing a water separator filter

Water and impurities can enter a boat's fuel tank in several ways, such as through incorrectly located fuel tank breathers and tank fillers, condensation forming in the fuel tank, or by purchasing contaminated fuel. While breathers and fillers can be replaced or relocated, condensation and contaminated fuel are more difficult to address. This is where a water separator filter comes in.

A water separator filter is a mechanical device installed in a boat's motor to act as an added layer of defence for its fuel system. It is designed to catch impurities and water before they reach the engine, preventing mechanical failure and allowing clean fuel to flow into the engine. Water separator filters target water by distinguishing the densities of water and oil, making them essential for vessels operating in water environments.

The presence of water and contaminants in fuel has been proven to cause clogging in engines. Regularly changing the water separator filter enhances engine efficiency, improves performance, and reduces maintenance costs. A clogged or damaged fuel water separator can cause issues such as engine sputtering, decreased speed and fuel efficiency, hard starting, and engine stalling.

When choosing a water separator filter, consider the clear bowl type, which allows you to see if water is gathering at the bottom of the system and drain it as needed. Installation is simple and typically takes between 15-30 minutes, with costs ranging from $50 to $85 depending on the brand and setup.

Frequently asked questions