Filter Wrenches

Oil Filter Wrenches and Fuel Filter Wrenches - Resources & Information

When it comes to performing an oil change or a fuel filter change for your outboard engine, Filter Wrenches are an essential maintenance tool to efficiently remove and install filters. 

PartsVu offers a complete selection of Filter Wrenches from OEM manufacturers and trusted aftermarket suppliers. Whether you need an adjustable filter wrench, Mercury filter wrench, and more, PartsVu has what you need to get the job done. 

Need help servicing your outboard engine? PartsVu regularly publishes helpful how-to guides and other valuable maintenance information to help boaters service their outboard engines. Browse our outboard maintenance blog for a wide range of relevant topics and see the FAQ section below, covering everything you need to know about maintaining your boat in confidence.

Filter Wrenches FAQ

What should I know about Filter Wrenches?

Here’s some info you need to know about Filter Wrenches:

• A marine oil filter wrench follows the same principles as a filter wrench that you’re probably familiar with from your automobile. Whether you’re using an adjustable filter wrench or a fitted OEM filter wrench (like a Yamaha oil filter wrench), you should be careful not to overtighten filters, refrain from using excessive leverage/overtorquing, and avoid damaging the filter.
• It’s best to use separate filter wrenches for different purposes. For example, keeping a fuel filter wrench and an oil filter wrench will prevent spilled gasoline fuel and contaminated oil mixing accidentally or entering separate systems. 
• When in doubt, purchase a OEM filter tool for specialized filter wrench repairs. This may include a Mercury fuel filter tool, Yamaha outboard fuel filter wrench, Volvo Penta fuel filter wrench, and others, but the concept is the same - the original manufacturer provides exact measurements that prevent slippage, overtorquing, and shearing off the threads that may cause leaks in the future. 

How do I perform maintenance on my Mercury MerCruiser outboard fuel system? 

Mercury MerCruiser fuel system maintenance is a critical aspect of 100-hour service. Depending on your application and style of boat, you likely have a fuel-water separating filter aboard your vessel. If you have not seen one, simply follow the routing of your fuel hose from the engine rigging tube backward through the boat. These vary in shape and manufacturer, so be sure to order an identical replacement filter. Use a filter wrench to loosen the existing filter element and use caution when removing it as it will be filled with gasoline.

A clear plastic or glass container is helpful to dump the filter into and to examine the contents. A small amount of debris is common, as is a small amount of water after the fuel has had a moment to settle. Larger amounts of water would warrant further investigation. If your filter’s mounting location allows it, pre-fill the replacement filter with some gasoline to make re-priming the fuel system easier later. It is also advisable to use a small amount of grease to lubricate the o-ring prior to installation. Spin on and hand tighten only about a half turn to snug.

Continue your Mercury fuel system maintenance by moving back to the engine and locate the filter element in the clear plastic bowl on the front of your block. Depending on your engine model, this filter cup may be removed by using a special cup wrench – or standard tools and a little caution. If applicable, unplug the water-in-fuel sensor and spin the cup off the housing. Again, drain into your clear container and examine the fuel. If your main water separator was free from water, this filter should be as well. Inspect the o-ring on the top of the filter cup and lightly grease for ease of installation or replace if needed. Replace the filter element with a fresh one and reinstall the cup. Use the cup wrench to tighten. Locate your engine’s primer bulb and use the primer to pump up the fuel system. You should observe gasoline entering and filling the filter cup. Check for leaks and prime until the bulb becomes firm. As a tip, primer bulbs work best when the arrow points up, so use any extra hose in the line to help you tilt the bulb vertical.

How do I remove the old oil filter from my Yamaha outboard motor? 

First, drain the spent oil from your Yamaha outboard motor. Then, work on removing the engine oil filter. Depending on your specific Yamaha outboard model, your marine oil filter may have a drain lip that will help keep the mess to a minimum when you unscrew the old filter. But most older engines don’t have this feature. Put down absorbent rags, or place a small cup below the filter prior to removal. Using a properly sized filter wrench or socket, loosen the filter. Yamaha produces a socket for their 5GH sized filters. Some technicians make a practice of puncturing the filter to allow trapped oil to drain back into the block prior to removal, but this will ruin your ability to take the filter apart later for further inspection should you wish.

How do I install a new oil filter and add fresh Yamalube marine oil?

Once you have inspected your spent oil and filter, set them aside for proper disposal. If you removed the drain screw to empty your oil, install a new crush gasket and reinstall the drain plug. The new oil filter should be removed from its package and the o-ring lubricated with a thin coat of fresh engine oil. Spin on the fresh oil filter and gently tighten with your filter wrench to seat the o-ring without over-torquing.

Loosen the yellow oil fill plug on the top of the engine and pour in fresh oil. Allow a few minutes for the oil to properly drain down into the oil pan with the engine trimmed down. Then, add just less than the stated capacity and check the oil level on the dipstick. Filling the oil to the lower level on the dipstick will help you to measure if the oil level changes over time. With your Yamaha 4-stroke marine motor oil change complete, you are now ready to move on to completing the rest of your 100-hour service.

What outboard engine tools should I have onboard?

Even if you don’t do your own maintenance, all boaters need some basic boat tools in their marine tool kits to help them out of a jam. Of course, if you plan to do your own maintenance or a portion of your own maintenance, you’ll need to be a bit better equipped.

So which boat tools should you have onboard? The following are our recommendations and the reasons behind them. Of course, the tools you should have onboard are significantly dictated by the type of boating you do. As a practical matter, a near-shore, freshwater boater needs fewer tools than an off-shore boater. While a problem close to the shore can be an annoyance, a problem off-shore might be a whole different matter.

• Fuel filter wrench—good idea to have on board if you get enough water or debris in your fuel system that a fuel filter change becomes necessary.
• Adjustable band filter wrench—you may need to change your fuel/water separating filter if you have water in your system or if you got some bad gas at the marina. US marinas nearly always sell high-quality filtered gasoline, but marines in the Bahamas are notorious for selling contaminated gasoline.
• Prop nut wrench—carrying this wrench only makes sense if you carry a spare prop. Many boaters carry a spare inexpensive aluminum prop in case they spin a hub or bend a blade so severely that it wobbles.
• Deck fill key/deck plate key/spanner wrench—these universal tools are designed to open all types and sizes of deck fill lids and shackles. Many of these tools also include bonus tools like bottle openers. Perfect for a cold one after fishing.
• Toolkit—if you have room on your boat, all-purpose toolkits can come in handy. 
• Pliers—channel lock, standard, and needle nose
• Leatherman–a very helpful all-purpose tool.
• Rigging knife
• Serrated knife—for cutting rope, your all-purpose tool might include a serrated blade.
• Flashlight
• Emergency plug set—in case a leak manifests while you are out on the water.
• Battery booster pack
• Battery terminal cleaner
• Zip ties—because we all know that you can fix almost everything with zip ties and duct tape.
• Duct tape

How do I service my Yamaha outboard fuel system?

Yamaha fuel system maintenance is a critical aspect of 100-hour service. Depending on your application and style of boat, you likely have a fuel-water separating filter aboard your vessel. If you have not seen one, simply follow the routing of your fuel hose from the engine rigging tube backward through the boat. These vary in shape and manufacturer, so be sure to order the identical replacement filter. Use a filter wrench to loosen the existing filter element and use caution when removing it as it will be filled with gasoline.

A clear plastic or glass container is helpful to dump the filter into and to examine the contents. A small amount of debris is common, as is a small amount of water after the fuel has had a moment to settle. Larger amounts of water would warrant further investigation. If your filter’s mounting location allows it, pre-fill the replacement filter with some gasoline to make re-priming the fuel system easier later. It is also advisable to use a small amount of grease to lubricate the o-ring prior to installation. Spin on and hand tighten only about a half turn to snug.

Continue your Yamaha fuel system maintenance by moving back to the engine and locate the filter element in the clear plastic bowl on the front of your block. Depending on your engine model, this filter cup may be removed by using a special cup wrench – or standard tools and a little caution. If applicable, unplug the water-in-fuel sensor and spin the cup off the housing. Again, drain into your clear container and examine the fuel. If your main water separator was free from water, this filter should be as well. Inspect the o-ring on the top of the filter cup and lightly grease for ease of installation or replace if needed. Replace the filter element with a fresh one and reinstall the cup. Use the cup wrench to tighten. Locate your engine’s primer bulb and use the primer to pump up the fuel system. You should observe gasoline entering and filling the filter cup. Check for leaks and prime until the bulb becomes firm. As a tip, primer bulbs work best when the arrow points up, so use any extra hose in the line to help you tilt the bulb vertical.

What is the difference between a primary filter and an in-line filter?

This Yamaha fuel filter is typically on the front, side, or rear of the powerhead, and is usually made of plastic you can see through. It filters fuel coming into the outboard. This “primary” filter usually features a small water trap at the bottom of the cup. This is the first filter after the 10-micron filter, so if there’s water in here, it’s time to change your 10-micron. On Yamaha outboards, there may be a red ring visible inside this filter. Don’t ever remove it. If it’s floating, you’ve got water in this filter’s trap and it time for a change. Shop Yamaha primary on-engine filters

Some models have an in-line filter between the Yamaha primary fuel pump and the VST (vapor separator tank) and/or in the fuel line between the VST and the fuel rail, located along the top of the outboard. Refer to your service manual or contact your dealer for the exact location for your model. Shop Yamaha in-line filters