Changing Fuel Filter: Yamaha 115 Outboard Maintenance Guide

Yamaha outboard engines are renowned for their performance and durability, and one of the key components that contribute to their smooth operation is the primary fuel filter. Over time, the fuel filter in your Yamaha 115 outboard engine will need to be replaced to maintain optimal performance and prevent engine damage. This guide will introduce you to the process of changing the fuel filter, ensuring your engine continues to run efficiently and effectively.

The fuel filter's location

The Yamaha 115 outboard engine has two fuel filters.

The first one is a small cup or strainer filter. To locate it, pull the engine cover off and follow the fuel line into the lower cowl. It is the first thing the fuel line touches. If you are facing the rear of the engine, it will be on the left-hand side.

The second fuel filter is inside the vapor-separating tank (VST). This is the tank that sits behind the intake manifold, and the high-pressure fuel pump sits inside it. The filter is below the fuel pump.

The tools and parts needed

To change the fuel filter on a Yamaha 115 outboard, you'll need the following tools and parts:

Tools:

A container or bag for the used fuel filter

Parts:

A replacement primary fuel filter (specific models include: Yamaha OEM Outboard Primary Fuel Filter Element 6D8-WS24A-00-00, Yamaha New OEM MAR-10MEL-00-00-4, Xislet 2PCS Primary Fuel Filter Element Compatible with Yamaha F40A F50/T50 F60/T60 F70 F90 F115 Outboard # 6D8-WS24A-00-00, 2 Pack 68V-24563-00-00 Fuel Filter Yamaha 50HP 60HP 75HP 90HP 115HP 4 Stroke Outboard Replaces Sierra 18-7979 Mercury 881540 filter 3 Microscopic OE Filtration Rating, 2PCS 68V24563 Fuel Filter Element for Yamaha 50 60 75 90 115 HP and Mercury 75 80 90 100 115 HP Microscopic Filter 881540 68V-24563-00, Boat Motor 6D8-24560-00 6D8-24560-01 Fuel Filter Assembly for Yamaha Outboard Engine 50HP 60HP 75HP 90HP 100HP 115HP, 8mm / 5/16in, 18-7866 Fuel Water Separating Filter 9-37807 Replacement for Ya-maha 115 HP Outboard Engines Rep MAR-10MEL-00-00 MAR-24563-00-00 MAR-FUELF-IL-TR, iFJF 6R3-24560-00-00 Fuel Filter Assembly 6R3245600000 Replacement for Yamaha 115 130 140 150 175 200 225 HP 2/4 Strokes Outboard Motor, SouthMarine Boat Motor 68V-24560-00 68V-24560-01 6D8-24560-08 6D8-24560-09 Fuel Filter for Yamaha 30HP-100HP 115HP, 8mm, 5/16", 2 Pcs 6D8-WS24A-00-00 Fuel Filter Replacement for Yamaha Marine Outboard 30hp-115hp 2006 & Later, 4 pack 68V-24563-00-00 Fuel Filter Fit for Yamaha 50HP 60HP 75HP 90HP 115HP for Mercury 881540 Sierra 18-7979, OEM Yamaha Mini-10 10-Micron Fuel/Water Separating Filter Only MAR-MINIF-IL-TR, 6C5-24251-00-00 Fuel Filter 18-79983 Compatible with Yamaha Outboard 4 Stroke 30 40 50 60 70 75 90 115 HP Motors, smseace 2pcs Primary Fuel Filter Element 6d8-ws24a-00-00 for Yamaha F40A/F50/T50/F60/T60/F70/F75/F90/F115 Outboard Fuel Filter, Fuel Filter 6D8-24563-00-00 Replaces for Yamaha Outboard 20HP 25HP 30HP 40HP 50HP 60HP 70HP 75HP 90HP 115HP（3 Pack）, 68V-24563 4PCS Fuel Filters for Yamaha 50 60 75 90 115 HP and Mercury 75 80 90 100 115 HP Outboard Engines 35-881540 68V-24563-00 18-7979, and Yamaha MAR-MINIF-IL-TR)

Step-by-step instructions

What you'll need:

• A replacement primary fuel filter
• A container or bag for the used fuel filter

Step 1: Inspect the Fuel Filter

Check the small black float in the filter. If it's on the bottom, this indicates no water in the fuel, which is a good sign.

Step 2: Remove the Water Sensor Plug

Gently pull to remove the plug.

Step 3: Prepare the Housing for Filter Removal

Loosen the fuel filter housing from the top cap manually. Do not use a wrench on the top cover, as it could crack the housing. When removing the housing, be cautious to ensure that the o-ring does not stick inside. If it's not seated properly when reinstalling, it could cause a fuel leak.

Step 4: Drain the Fuel

Drain the fuel from the fuel filter housing before removing the old filter. Check the drained contents for any water in the fuel. Clear fuel without droplets indicates that everything is in good condition.

Step 5: Check the Fuel Type

The colour of the fuel element indicates the fuel type. Green indicates non-ethanol fuel, while brown suggests a high ethanol content.

Step 6: Remove the Old Fuel Filter

Carefully remove the old fuel filter.

Step 7: Install the New Fuel Filter

Place the new fuel filter into the housing.

Step 8: Reattach the Housing

Thread the housing back onto the top cover. If you use ethanol fuel, you may find it more difficult to tighten the housing as the ethanol can soak into the plastic threads. Applying a small amount of marine grease can help with this.

Step 9: Reconnect the Water Sensor Plug

Remember to plug the water sensor back in. This sensor is crucial as it alerts you if water gets into the system, which could cause the engine to misfire or vibrate erratically.

How to identify when a change is needed

Knowing when to change the fuel filter on your Yamaha 115 outboard engine is crucial for maintaining optimal performance and engine health. Here are some detailed signs to watch out for that indicate it's time for a change:

• Engine Issues: Frequent stalling or misfiring of the engine suggests a clogged fuel filter. This means the filter is obstructing the fuel flow, preventing sufficient fuel from reaching the engine.
• Decreased Fuel Economy: If you notice a significant drop in your boat's fuel efficiency, it could be a sign that the fuel filter is blocked. As a result, the engine has to work harder, leading to increased fuel consumption.
• Starting Difficulties: If you're experiencing difficulty starting the engine, it might be due to a clogged fuel filter. This issue prevents the required amount of fuel from reaching the engine for smooth operation.
• Loss of Engine Power: A decline in engine power, especially during acceleration, could indicate that it's time to replace the fuel filter.

In addition to these signs, it's important to consider the usage of your boat and the quality of fuel used. For regularly used boats, it is recommended to change the fuel filter annually or every 100 hours of operation, whichever comes first. If you often operate in areas with unreliable fuel quality, more frequent replacements may be necessary to prevent engine damage caused by contaminated fuel.

Remember, timely attention to these signs and adhering to the recommended maintenance schedule will ensure the continuous health and efficiency of your Yamaha 115 outboard engine.

The function of the fuel filter

The fuel filter is an essential component of a boat's fuel system, and plays a critical role in maintaining the engine's performance and longevity. Here's an overview of its function:

Filtering Impurities: The primary function of the fuel filter is to remove impurities, such as dirt, debris, water, and other contaminants from the fuel before it reaches the engine. This is crucial as marine engines consist of small parts that are easily clogged, and contaminants can lead to poor engine performance and internal corrosion. By filtering out these impurities, the fuel filter ensures that only clean fuel enters the engine, maintaining optimal engine performance and fuel efficiency.

Preventing Engine Damage: The fuel filter acts as a safeguard, preventing severe damage to the engine by blocking larger particles that could harm its internal components. Without a properly functioning fuel filter, the engine is at risk of long-term damage, which can be avoided with regular filter replacements.

Optimizing Engine Performance: A clean and well-maintained fuel filter optimizes the boat's performance. It ensures the engine receives an uninterrupted supply of clean fuel, enhancing the engine's durability and lifespan.

Maintaining Fuel Efficiency: By ensuring the fuel is free of contaminants, the fuel filter helps maintain the fuel efficiency of the outboard motor. A clogged filter, on the other hand, can lead to increased fuel consumption as the engine has to work harder to pull fuel.

Facilitating Safe Operations: The fuel filter contributes to the overall safety of the boat by reducing the risk of engine stalls, misfires, and loss of power. It achieves this by ensuring a consistent supply of clean fuel to the engine, thereby reducing the chances of unexpected engine issues during operation.

To maintain the health of your Yamaha outboard engine and ensure optimal performance, it is essential to replace the primary fuel filter regularly. This maintenance task is straightforward and can be performed by following a step-by-step guide specific to your Yamaha model.

Frequently asked questions