How To Change A Water Pump On An Outboard Motor

Replacing An Outboard’s Water Pump

1. In order to get access to the water pump, the gearcase must be dropped and the mounting nuts removed. Outboard water pumps are made in a straightforward manner. They’re conveniently located on top of the lower gearcase assembly, making them simple to reach and maintain. The pump is equipped with a rubber impeller that is linked to the engine’s driveshaft. Flow of water into the lower gearcase is accomplished by inlets located on the sidewalls of the gearcase, directly above the region of the propeller shaft.

The pump pumps water up into the housing by drawing it via the intakes.

When the pump is turned on, water is discharged from the top of the housing through a brass tube, which is normally half an inch in diameter, and up to the engine’s powerhead, where it circulates through the system’s cooling passageways.

For this reason, the majority of outboard specialists recommend replacing them every season, or at the very least every other season.

• There are a slew of anecdotes that go like this: “I’ve owned my outboard for twenty years and never updated the water pump.” 2.
• Before removing the trim tab, make a note of where it is so that you can reinstall it in the proper location the next time.
• 3.
• While the author is doing the water pump work, it is important to note that the gearcase is also being emptied of old oil.
• Place all of the pieces on a clean towel and label them.
• 5.
• The old impeller’s blades (on the right) have been worn down; compare this to the new impeller (on the left).
• It is important to use an appropriate sealant on gaskets in order to decrease the possibility of leaks.
• With a small clockwise twist, the impeller is forced into the housing lining of the housing.
• 9.

Backyard Mechanic

Removal of the mounting bolts is required before to lowering the gearcase in order to have access to the water pump A simple design is used for these water pumps. They’re also convenient to reach and service because they’re located directly on top of the bottom gearcase assembly. Pump housing with a rubber impeller that is keyed to the engine’s driveshaft Flow of water into the lower gearcase is accomplished by inlets located on the sidewalls of the gearcase, right above the place where the propeller shaft would be.

1. Water is drawn into the housing by the pump, which draws it via the intakes.
2. Typically, a brass tube about a half-inch in diameter is used to transport water from the top of the housing to the engine’s powerhead, where it circulates through the cooling system’s passageways and out the top of the housing.
3. For this reason, the majority of outboard specialists recommend replacing them every season, or at the very least every two seasons.
4. 2.
5. Before removing the trim tab, make a note of where it is so that you can reinstall it in the proper location after you are through.
6. 2.
7. While the author is finishing up the water pump repair, it is important to note that the gearcase is being emptied of old oil.
8. On a clean towel, lay out and label all of the pieces, and then remove the old pump housing and impeller.
9. In order to limit the likelihood of leakage, it is essential that suitable sealant be used on gaskets.

Afterwards, the housing and impeller assembly are gently lowered into the driveshaft’s flat with the aid of an impeller key in the flat. 9. Take care not to overtighten the screws that attach the housing to the chassis.

Stand It Up

Installing the lower unit on a work stand is recommended. Clamping the skeg tightly in a vice may suffice; however, protecting the finish by cushioning the jaws of the vise with a cloth or other soft material can be beneficial in this situation. You may now remove the old water pump from the unit after it has been secured.

Re-installation

It is important to remember that the gearcase must be in the proper gear before installing it. You shouldn’t have moved the shift rod at all when fixing the water pump, is what I’m saying. When reinstalling the unit, make sure you do the following:

• After cleaning the top of the drive shaft, dab a little quantity of marine oil on the splines — NOT on the top — and allow it to dry completely. Greasing the top of the shaft may hinder the shaft from correctly fitting inside the crankshaft. The splines will be easier to remove the next time the gearcase is removed if they are greased.

• Make certain that the exhaust adapter is appropriately positioned in the middle of the vehicle.

• While moving the unit up into the middle, check to see that the drive shaft, shift shaft, and water tube are all in the appropriate positions before continuing. It is also important to ensure that the water tube reaches the top of the water pump properly
• If it does not, the engine will not receive cooling water and will overheat as a result.

• Start the engine and check to see that it is pumping water, running properly at the right temperature, and shifting correctly when the installation is complete and the shift shaft and shift cable have been linked. Additionally, consider servicing the engine’s thermostats at the same time, to ensure that the complete cooling system is refreshed and ready for service

General Tips

Follow the instructions for replacing the water pump in the factory handbook to the letter, paying close attention to any cautions or warnings that are included. Some broad guidelines that apply to most water pumps, regardless of brand or engine size, are as follows:

• Clear the intake passages and the top of the gearcase around the pump using compressed air to ensure that there is no debris in the system. Using an air pistol with an extended tip to reach deep into the intake passageways and blow away any collected sand or silt may save time and effort when replacing the pump and impeller plate. In order to clean any debris from the brass water tube in the middle of the engine, blow compressed air into it.

• When the handbook specifies which sealants to use, follow the instructions.

• To ensure appropriate rotation (clockwise) while inserting the impeller into the housing, first ensure that the impeller is turned (clockwise)
• Next, while still rotating the impeller, install it into the housing while turning it so that the blades compress in the proper direction.

• When fitting the impeller into the housing, dab a small amount of non-petroleum-based oil over the blades of the impeller to ensure that it is somewhat pre-lubricated when the engine is restarted once it has been fully reassembled. Additionally, this facilitates the process of squeezing the blades into the housing.

• Take care not to over-torque the housing screws, otherwise you risk cracking the housing and causing a leak later on, which might result in overheating.

• Draining, checking, and refilling the gear lubricant is a good idea once you’ve finished with the pump installation, so do it right away.

Author

BoatUS Magazine is a publication to which I contribute. John Tiger is a freelance boating writer who contributes to a variety of periodicals on a regular basis.

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Replacing An Outboard Water Pump

According to a general rule of thumb, the impeller of the water pump should be replaced every two seasons. An outboard water pump repair kit is available for nearly all of the models on the market. When performing actions that necessitate the use of lubricant, BRP Triple-Guard Marine Grease or Mercury 2-4-C Marine Lubricant should be used.

Step 1:Step 1

Input the reverse gear into your vehicle’s transmission.

Step 2:Step 2

The fasteners that connect the bottom unit to the middle should be removed.

Step 3:Step 3

Disconnect the shift rod from the transmission. Not all shift rods are designed to be disconnected in the same way. Some disconnect above the gearcase, some disconnect above the powerhead, some disconnect below the swivel bracket, and some disconnect below the swivel bracket.

Step 4:Step 4

Remove the lowest unit from the equation.

Step 5:Step 5

Remove the nuts that hold the water pump housing together.

Step 6:Step 6

Take the water pump housing and impeller out of the gearcase and set them aside.

Step 7:Step 7

The water pump housing and impeller should be removed from the gearcase.

Step 8:Step 8

Replacement of the water pump worn plate and gaskets on the gearcase is required.

Step 9:Step 9

Ensure that the impeller cup, keyway, and driveshaft are all lubricated.

Step 10:Step 10

Install the impeller so that it is parallel to the impeller key.

Step 11:Step 11

Install the housing for the water pump. As you lay the housing on top of the impeller, turn the driveshaft to center it. For vehicles with standard (right-hand) rotation, you will spin the driveshaft in the clockwise direction.

Step 12:Step 12

Tighten the housing nuts in a crisscross manner to ensure that the gasket is well sealed.

Step 13:Step 13

In the water pump housing, install the replacement water tube seal.

Step 14:Step 14

While installing the bottom assembly, be sure to align the driveshaft, water tube, and shift rod.

Step 15:Step 15

While assembling the bottom section, make sure to align the driveshaft, water tube, and shift rod.

• It is possible that you may need to connect the shift rod before you can bolt up the bottom section.

Step 16:Step 16

Please keep in mind that this is not a comprehensive guide on replacing a marine water pump. Always refer to your boat’s instruction manual or the manufacturer’s website for model-specific information. The motor water pump is a critical component of any outboard engine, yet the majority of people can’t recall the last time they had their water pump repaired, let alone completely replaced. That being the case, it’s probably time to replace the device in question. The use of marine engine cooling pumps and water pump impellers can assist to extend the life of the engine in your outboard boat.

However, if you are utilizing a water pump that is broken or worn out, it might result in expensive repairs. How to detect whether a water pump is faulty and how to replace it when the time comes are topics we’ll be discussing today.

How to Tell if a Water Pump Is Bad

The following is not a thorough guide on replacing a marine water pump in every situation and circumstance. Always refer to your boat’s instruction manual or the manufacturer’s website for model-specific guidance. Most individuals cannot recall the last time they had their motor water pump repaired or even changed, despite the fact that it is a critical component of any outboard. Und if this is the case, it is most likely time to replace the item in question. Water pump impellers and cooling pumps for outboard engines both assist to increase the life of the engine in your outboard boat.

We’re going to look at how to identify if a water pump is faulty and how to replace it with a new one when the time is right.

1. The outboard motor is overheating
2. It has to be replaced. The impeller is on borrowed time
3. He is wasting his life. It appears that the stream of water coming from the cooling water outflow has been lowered

1. The Outboard Engine Is Overheating: When the water temperature around your outboard motor begins to rise, it is a reason for concern. In addition, if the motor is unable to create a consistent stream of water once it has achieved the proper working temperature, one of two possible explanations is most likely the impeller, which is most likely significantly worn or broken in some way. While it is unusual, wasps can also be a problem since they like to burrow in the cooling water exit during the winter. The Impeller Is Living on Borrowed Time: The Impeller is living on borrowed time. Each spring, as you prepare your boat engine’s water pump, make sure to thoroughly examine the impeller. The impeller of your marine engine’s water pump has a service life of around 300 operational hours or three years, whichever comes first, according to the manufacturer. The impeller should be replaced if it has been more than a certain number of years or operational hours. It appears like the flow of water from the cooling water outlet has been reduced: In the event that you’re going on your first expedition of the season and you notice a reduced stream of water flowing from the cooling water outlet, it’s probable that it’s wasps once again. To rule this out, gently introduce a tiny wire into the outlet and poke about with it to see what you can find. In the event that this isn’t your first expedition of the season and you’re observing a diminished stream of water, you most likely have a broken pump housing or impeller.

How to Replace an Outboard Water Pump

Outboard motors are more dependable than they have ever been. Parts and components will, however, need to be replaced on a regular basis, just as they would with any other motor. Every year or every 100 running hours, whichever comes first, it is advised that you examine the impeller of your marine water pump. A detailed maintenance plan for your outboard water pump may be found in the operator’s handbook for the particular model you have. It is easier to detect problems with your raw water pump if you inspect it on a regular basis and check it thoroughly.

How to Remove and Replace an Old Engine Water Pump:

1. Put the Motor in Reverse: First, put your motor in reverse gear
2. Then, put your motor in neutral. Remove the bolts from the nut. Next, you’ll want to remove the mounting nuts that hold the lower unit to the middle, as well as any bolts under the trim tab, and then you’ll be able to disconnect the shift rod. To ensure that you install the bolts accurately, it’s a good idea to indicate the location of the bolts before removing them. Then, remove the shift rod from the vehicle. The fact that not all shift rods disengage in the same manner should not be overlooked. Some disconnect below the swivel bracket, while others disconnect by the powerhead, and yet others disengage above the gearbox. Refer to your product’s instruction booklet for particular product instructions. Remove the Lower Unit and Bolts from the vehicle: Once the shift rod has been removed, you’ll need to remove the bottom unit as well as the nuts that hold the water pump housing in place. Before removing the bolts, make a note of their location on the drywall. Remove the Water Pump from the system. Arrangements for housing and the impeller: You should now be able to simply remove the engine water pump housing and impeller from the gearcasing with your hands. Additionally, you may remove the wear plate and gaskets from the gearcase at this time as well. The following steps are required to install the new marine water pump plate and gaskets: Read the installation instructions for your new water pump thoroughly before proceeding. Then, on the gearcase, put the marine engine water pump wear plate and gaskets that came with it. Make certain that you are putting the right sealant on the gaskets in order to limit the likelihood of leaks. Lubricate:Once the impeller cup, keyway, and driveshaft are in place, you may lubricate them as needed. Installing the Impeller is as follows: Install the impeller so that it is aligned with the impeller key after that. Install the Marine Water Pump Housing:The next step is to install the water pump housing, which is typically done by pushing the impeller into the housing liner with a little clockwise twist
3. Install the Marine Water Pump Housing As you set the housing on top of the impeller, turn the driveshaft to ensure that it is secure. For most normal rotation models, you’ll want to spin the driveshaft in the opposite direction of the rotation. Then, in a crisscross pattern, tighten the housing nuts to ensure a tight gasket seal is achieved. In the water pump housing, insert the new water tube seal you just made. Then, when installing the bottom unit, make sure the driveshaft, water tube, and shift rod are all aligned. Take care not to overtighten the screws that hold the housing in place. Oil and reinstall the bolts that connect the lower unit to the midsection: At this point, you’ll want to lubricate and reinstall the bolts that connect the lower unit to the midsection. Please keep in mind that you may be required to attach the shift rod before you can begin to bolt up the bottom unit. Start the engine: Finally, turn on the motor and flush it to confirm that the stream of water remains steady throughout the process. If that’s the case, you’re all set and ready to go

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How to Install a Water Pump in a Mercury Outboard Motor

Replace the water pump on your Mercury outboard, and you’ll be tampering with the engine’s peripheral workings that, well, keep the motor running smoothly. The pump is operated by the same drive shaft that powers the propeller, and the pump itself is little more than an impeller enclosed in a casing with a pair of gaskets on the outside. Nonetheless, it’s something you’ll have to do at least once a year, so plan it as a winter activity that won’t interfere with your boating enjoyment.

Items you will need

• Replace the water pump on your Mercury outboard, and you’ll be messing with the engine’s peripheral components that keep it running smoothly. In fact, the pump is operated by the same drive shaft that powers the propeller, and the pump itself is little more than an impeller in a housing that is sealed with a pair of gaskets. Nonetheless, it is something that must be done at least once a year, so make it a winter chore that will not interfere with your boating enjoyment.

Drop the Lower Unit

Replace the water pump on your Mercury outboard, and you’ll be tampering with the engine’s peripheral components that keep it running. The pump is operated by the same drive shaft that powers the propeller, and the pump itself is little more than an impeller in a housing with a couple of gaskets. You’ll have to do it at least once a year, so make it a winter chore that won’t interfere with your boating enjoyment.

Step 2

Remove the trim tab from the bottom of the plate above the propeller by using a combination wrench or socket of the proper size to remove the bolt.

Remove the bolt that is located under the trim tab. Remove the nuts from the bolts that hold the bottom unit in place and set them aside.

Step 3

Position yourself on one side of the outboard, near the junction that connects the bottom unit to the remainder of the outboard’s body. Position your assistant on the other side of the room. Remove the bolts holding the bottom unit in place, starting with the ones closest to the floor and working your way up. Unless you are very careful, the drive shaft and shift rod can be bent if they are not pulled away from the outboard’s engine housing quickly enough. While you are removing the two bolts, have a helper hold the unit in place.

Step 4

Assume a position on one side of the outboard, near the junction that connects it to the remainder of the outboard. Place your assistant on the other side of the room. a. To begin removing the bolts that hold the bottom unit in place, start with the ones that are closest to the ground. The drive shaft or the shift rod might be bent if you neglect to remove the shaft and rod from the outboard’s engine housing when you should. Maintain the unit’s stability while you remove the two bolts with the assistance of a helper.

Replace the Pump

Take a look at the top of the bottom unit; you’ll notice that the water pump is located around the drive shaft, which is where it enters the unit. Remove the four bolts that hold the pump housing in place and set them aside. Remove the pump casing from the driving shaft in order to reveal the impeller within.

Step 2

Remove the impeller from the pump. As you do so, a little, square piece of metal, known as a Woodruff key, will fall off the driveshaft; this is the key that holds the impeller to the driveshaft and allows the impeller to rotate. Keep the key in a safe location and open the pump replacement package. Prepare the workstation by laying out the items of the kit.

Step 3

Only those parts of the pump that are included in the replacement kit should be removed. Make use of a paint scraper to remove any remaining gasket material from the top of the bottom unit. Attach the gaskets from the kit to the lower unit using a marine gasket compound, such as Mercury’s Perfect Seal, to keep the water out.

Step 4

White marine grease should be used to coat the inside of the new pump housing. Apply a little amount of lubricant on the Woodruff key and insert the key into the driveshaft again. Place the impeller on the driveshaft and tighten it down. Apply Perfect Seal to the threads of the pump housing bolts and then thread the housing bolts through the bores in the pump housing and into the bottom unit to complete the installation.

Step 5

White marine grease should be applied to the inside of the new pump housing. Return the Woodruff key to the driveshaft after applying a little amount of lubrication. Place the impeller on the driveshaft so that it is parallel to the ground. Perfect Seal should be applied to the threads of the pump housing bolts before threading the housing bolts through the bores in the pump housing and into the bottom unit.

Reinstall the Lower Unit

Mercury Perfect seal should be applied to the threads of the bottom unit bolts. Remove the lower portion from the vise by loosening the jaws and moving it to the outboard.

Slide the drive shaft and shift rod into the outboard position without allowing them to come into contact with the exhaust housing’s sidewalls. Slide the drive shaft upward until it engages the splines on the engine block.

Step 2

Lower unit bolts should be replaced in the same sequence as they were removed from the top unit. Install the nuts on the bolts and check that the water tube connection is properly connected with the water tube. Installation of the remaining nuts and bolts (apart from the one that goes under the trim tab) that secure the bottom section to the engine and tightening to 35 foot-pounds

Step 3

80 inch-pounds should be applied to the bolt under the trim tab. Replace the trim tab and lower the engine using the trim-tilt mechanism to get the desired result.

• Before conducting any repair on the boat’s engine, disconnect the negative cable from the battery with a 5/16-inch box end wrench and store the cable in a safe place. Removing the cable from the battery and moving it outside of the battery box is necessary before closing the battery box lid. Immediately after the job is finished, reconnect the negative battery cable. When working on the motor of your boat, you should use a propeller wrench to remove the propeller nut. Remove the thrust hub, propeller, and washers from the propeller shaft by sliding them apart. In the event that a propeller is not removed before working on an engine that has been removed from the water, a propeller-strike accident may occur, which can cause serious damage or death.

• Possessing an outboard motor entails owning a set of tools. Have a variety of open- and box-end wrenches in a variety of sizes, as well as a large assortment of sockets up to 1 1/2 inches in diameter

Outboard motor ownership entails the acquisition of related equipment and supplies. Assemble a variety of open and box ends in various diameters, as well as a large assortment of sockets up to 1 1/2 inches in diameter.

• From 1987 through 1993, Mercury Marine published a service manual for its Mercury/Mariner outboard motors (models 70, 75, 80, 90, 100, and 115). 70, 75, 75 Marathon 75XD, 75 SeaPro, 80, 90 3-Cylinder, Serial Numbers 0A9960142 Thru 0D283221, and 1988 through 1993 100, 115 (4-Cylinder), Serial Numbers 0B209468 Thru 0D283221
• 70, 75, 75 Marathon 75XD, 75 SeaPro, 80, 90 3-Cylinder, Serial Numbers 0A9960142 Thru 0

• The Mercury Marine Service Manual for Mercury/Mariner Outboards (Models 70-75-80-90-100-115) is available for download at the link below. 70, 75, 75 Marathon 75XD, 75 SeaPro, 80, 90 3-Cylinder, Serial Numbers 0A9960142 Thru 0D283221
• 1988 through 1993 100, 115 (4-Cylinder), Serial Numbers 0B209468 Thru 0D283221
• 70, 75, 75 Marathon 75XD, 75 SeaPro
• 70, 75 Marathon 75XD, 75 SeaPro

• Before conducting any repair on the boat’s engine, disconnect the negative cable from the battery with a 5/16-inch box end wrench and store the cable in a safe place. Removing the cable from the battery and moving it outside of the battery box is necessary before closing the battery box lid. Immediately after the job is finished, reconnect the negative battery cable. When working on the motor of your boat, you should use a propeller wrench to remove the propeller nut. Remove the thrust hub, propeller, and washers from the propeller shaft by sliding them apart. In the event that a propeller is not removed before working on an engine that has been removed from the water, a propeller-strike accident may occur, which can cause serious damage or death.

Biography of the Author Will Charpentier is a writer who specializes in topics related to boats and the marine environment. Charpentier, a retired ship captain, holds a degree in applied ocean science and engineering from the University of British Columbia. He is also a trained marine technician and the author of a popular manual on writing local history, which has been translated into several languages.

How to Install a 40Hp Outboard Motor Water Pump

You wouldn’t put a $5,000 outboard engine at danger for the sake of a $60 water pump, would you? Even if you are not technically inclined, changing the water pump on an outboard motor does not need dismantling the engine. When you’re done, you’ll have opened a cover and pushed everything back into place. When the water pump on your 40-horsepower outboard needs replacing, you can do it yourself using a tool to loosen a handful of bolts and a new part that only fits one way.

Items you will need

• Towels that have seen better days
• Box-end wrench, socket wrench, water-resistant marine lubricant, pump replacement kit, torque wrench are all included.

towels that have seen better days. Bench vise, box-end wrench, socket wrench, waterproof marine lubricant, pump replacement kit, torque wrench

• Remove the nut from the negative battery post, which is marked with the letters “NEG” or a minus sign, and raise the cable away from the battery while working on your motor. Because it separates the electrical supply from the boat’s common ground, you may work on the boat’s electrical or mechanical systems without worrying about the motor starting or another system being electrified.
• To work on your outboard motor while your boat is on its trailer or while your motor is on a storage stand, remove the propeller nut with a 1 1/16-inch wrench and carefully pull the thrust hub, propeller, and washers off the propeller shaft using a 1 1/16-inch wrench. Failure to remove a propeller before driving an outboard out of the water for repair or long-term storage puts the boater at risk of a propeller-strike injury, which can be fatal or severely disfigure him or her.

References

• In 2007, Seloc Marine published “Johnson Repair Manual 2.5 to 250 HP Models, 2002-2007,” “Mercury Marine Outboard Repair Manual 2 to 250 HP 1990-2000,” “Evinrude Repair Manual 2.5-250 HP,” and “Mercury Marine Outboard Repair Manual 2 to 250 HP 1990-2000.”

• Remove the nut from the negative battery post, which is marked with the letters “NEG” or a minus sign, and raise the cable away from the battery while working on your motor. Because it separates the electrical supply from the boat’s common ground, you may work on the boat’s electrical or mechanical systems without worrying about the motor starting or another system being electrified.
• To work on your outboard motor while your boat is on its trailer or while your motor is on a storage stand, remove the propeller nut with a 1 1/16-inch wrench and carefully pull the thrust hub, propeller, and washers off the propeller shaft using a 1 1/16-inch wrench. Failure to remove a propeller before driving an outboard out of the water for repair or long-term storage puts the boater at risk of a propeller-strike injury, which can be fatal or severely disfigure him or her.

Biography of the Author Will Charpentier is a writer who specializes in topics related to boats and the marine environment. Charpentier, a retired ship captain, holds a degree in applied ocean science and engineering from the University of British Columbia. He is also a trained marine technician and the author of a popular manual on writing local history, which has been translated into several languages.

How to Change the Water Pump on a 1997 120HP Force Outboard Motor

Force was a manufacturer of outboard motors from the early 1980s till 1999. Despite the fact that Force outboard motors are no longer manufactured, many individuals still possess them, and replacement parts are still quite simple to come by. It is necessary to repair your Force outboard’s water pump on a regular basis since it is subjected to a lot of wear and strain. The water pump is responsible for drawing in water and circulating it around the engine to keep it running cool.

Step 1

Disconnect the bolts that connect the bottom unit of your motor to the top unit of the motor by yanking them out. Grabbing the lower unit, place it where you will be working on it is the first step.

Step 2

Remove the four holding bolts that hold the water pump housing in place and slide the pump housing down and away from the drive shaft.

Step 3

Remove the four retaining bolts holding the water pump housing in place and push the pump housing down and away from the drive shaft to complete the removal.

Step 4

Before you begin, align the face plate of the water pump and hand-thread the four retention bolts until they are fully threaded. Using the socket set, tighten them down. Remove the lower unit from the motor and position it at the bottom of the motor. Continue to hold it in place while you manually tighten the retaining bolts. Using your socket set, tighten them down. References

• Edwin R. Sherman’s “Outboard Engines: Maintenance, Troubleshooting, and Repair, Second Edition” was published in 2008 and is available online.

What You’ll Need to Get Started Ashton Daigle is a journalist who grew up in New Orleans and graduated from Southeastern Louisiana University in 1998. He began his career as a reporter shortly after graduation. In 2005, he was faced with the most significant news event of his career: Hurricane Katrina. In his spare time, Daigle is working on an anthology of articles titled What It Means to be a Saints Fan.

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Speak with other boaters and you will likely discover that many owners have no idea what they are talking about when it comes to the water pump, let alone how to recognize when they have a defective outboard water pump. However, this critical component must be repaired on a regular basis in order to ensure the longevity of your outboard. An outboard water pump that is not functioning properly can result in lower water pressure than normal. In some cases, the outboard will cease pumping water out of the tell-tale, overheat, and reduce the available RPM, causing substantial damage if the problem is not addressed immediately.

In many circumstances, all that is required is a replacement of the impeller on the water pump!

What is an Outboard Water Pump?

Outboard water pumps are not difficult to use. It is conveniently situated directly above the bottom gear case assembly, making it simple to maintain and repair. The impeller of the pump is made of rubber and is keyed to the driveshaft, which is housed within the pump housing. Pump impeller rotation is caused by the water entering the lower gear case through the inlets located on one side of the lower unit and being turned by the driveshaft. The water is drawn into the housing by this pump, which is connected to the intakes.

Whenever the engine begins to crank up, these blades begin to move away from the lining.

In order to ensure that it circulates through the engine’s cooling tubes, it goes up via the power head of the engine.

How Do I Know if My Boat Water Pump is Bad?

It is not difficult to operate outboard water pumps. It is easily accessible because it is placed just above the bottom gear case assembly. The impeller of the pump is made of rubber and is keyed to the driveshaft, which is located inside the housing. Pump impeller rotation is caused by the water entering the lower gear case through the inlets located on one side of the lower unit. The water is drawn into the housing by this pump, which is powered by a motor. As the driveshaft rotates, the blades of the impeller, also known as vanes, make contact with the lining of the engine.

Whenever the engine starts to crank up, these blades begin to move away from the lining. A brass tube connects the pump’s housing to the outside world, where it pumps water. In order to ensure that it circulates through the engine’s cooling channels, this passes up via the engine’s power head.

How Do You Test an Outboard Water Pump?

On many outboards, you may start the engine by merely putting on the muffs and turning the key. An even stream of water should be streaming out of the openings in the engine’s hood as it cools. There are a few brands that actually produce a stream, albeit it may not appear to be consistent. While this may appear to be worrying, it is totally usual for those models in that situation. Simply said, it is dependent on the sort of outboard motor you have. It is also vital to keep this in mind while wearing the muffs.

• Others will.
• Then there’s the situation when the engine is submerged in water and is subjected to the back pressure of the water, and the bottom unit is completely submerged in water.
• Depending on the sort of instruments you have on your boat, you can also check your gauges on the horizon.
• At idle, the majority of impellers will create between 1-3 PSI of pressure.
• However, this varies depending on the age, RPM, and type of the outboard and impeller.
• It should be changed on a regular basis regardless, because it is the most common cause of water pump failure.

Why is My Outboard Not Pumping Water?

Many outboards allow you to start the engine by merely putting on the muffs. An even stream of water should be streaming out of the perforations in the engine’s hood as you watch. Even though certain brands produce a stream, it may not appear to be continuous. While this may appear to be worrying, it is totally typical for those models to experience this phenomenon. It all comes down to the sort of outboard motor you have in your vehicle. Furthermore, while wearing the muffs, it is vital to keep this in mind: A few of those types will not generate enough suction to force water out of the tell tale or the holes on the top of the bottom unit.

• The reason for this is that the garden hose and muffs have less water pressure than normal.
• Increasing the likelihood that the impeller will be submerged.
• Most modern versions will display the amount of water pressure that is being produced directly on your dial.
• Later, at full power, the pressure might reach 20-25 PSI.

The impeller of an outboard water pump can be replaced if you are unclear of how the pump is performing. Regardless, it should be replaced on a regular basis because it is the most common reason for water pump failure.

Step1: Check the Water Pump Impeller

The impeller of the water pump is the most common source of circulation problems and overheated engines. This tiny, circular disc is equipped with rotating blades that transport water through the device. The failure of this component causes the engine to overheat because it prevents the flow of water to the engine from being interrupted. As a result of the low cost and ease of installation of this item, it is recommended to maintain a spare on hand. It should be changed on a regular basis as part of your outboard boat maintenance routine.

Step2: Evaluate the Water Intake

After turning off the boat’s motor, look around for any material, such as garbage or weeds, that might be obstructing the water intake. If you see a foreign object, remove it as soon as possible. After that, restart the engine to determine whether the problem has been fixed.

Step3: Inspect the Water Output

The majority of outboard motors have a water output, which is convenient. This little tube has the potential to become clogged. When this happens, the water flow is disturbed, which causes problems for the engine to run. To test the output, take a little length of wire and pass it through it. Remove any material that may have been trapped within by wriggling it around. The water flow should be consistent in the majority of outboards. In addition, you want the water that comes out to be warm, but not overly hot.

Step4: Check the Thermostat

While this isn’t a typical problem, it is something to keep an eye out for. Naturally, if the engine is not getting hot enough to sustain temperature, you should replace the outboard thermostat as soon as you notice the problem. If you don’t, you run the risk of completely destroying the power head.

What Happens When Impeller Goes Bad?

Water pump failure is frequently the consequence of a faulty impeller, which may be easily repaired. What is the impeller’s function? The impellers circulate cold water through the engine, allowing it to cool down. The impeller is made up of a series of rubber vanes that are molded around a central hub to create rotation. There are a variety of reasons why these flexible vane tips wear out, none of which can be avoided. Aside from that, if the outboard engine is left unused for an extended period of time, the impeller might become brittle and rigid, leaving it useless.

Water is required for the lubrication of the impeller.

Detecting problems with the impeller as soon as possible is your best bet.

Here are a few warning signals to look out for:

Overheating Outboard

If the temperature of the engine begins to rise, you should be concerned. It’s possible that your problem is caused by a faulty impeller.

Additionally, you should inspect the cooling water outlet, which is situated on the bottom rear of your motor’s top cowling at the bottom of the motor’s top cowling. If you’ve had the boat in storage for a while, it’s possible that bugs have made themselves at home in the storage space.

Reduced Water Stream from Cooling Water Outlet or Tell Tale

When the flow of water is limited, it is possible that a blockage will occur. In order to corroborate your suspicions, insert a small wire into the outlet. If you have previously taken the boat out without experiencing any issues, it is possible that the pump housing has been broken. Look for a crack or a hole in the water pump. Aside from that, if the pressure has just fallen, you can discover that a broken or worn impeller is to blame for the problem.

Lack of Service for Impeller

If you haven’t replaced out the impeller in a while, you might want to do it right away to avoid any problems. As you make your winter preparations, make sure to check the water pump. You should consult the manufacturer’s instructions to determine how frequently your impeller should be replaced. Some recommend that you do it once a year, while others recommend that you do it every three years. Whatever the time range, don’t skip out on this critical preventative maintenance step!

How Often Should You Change Your Outboard Water Pump?

Really, it all relies on how you operate it and what the manufacturer recommends. The water pump itself should not need to be replaced, but the impeller should be the first thing you check. You will need to change the impeller more frequently than other boats, if you are a thin runner who pumps a lot of sand into the water. The vast majority of manufacturers and experts advise that you should not use the present impeller for more than three years before replacing it with a new one. If this is not done, the bolts on the bottom unit may come loose, resulting in increased wear on the impeller.

How Much Does it Cost to Replace an Outboard Water Pump?

Most water pump repair kits, which include the impeller, are available for less than $100, and they are quite affordable. Installing this yourself will save you a significant amount of money in the long run. As an alternative, a shop may charge you for an hour or two, which may result in an hourly cost ranging from $100 to $350, depending on where you take your vehicle. Listed here are the measures to take if you decide to undertake your own outboard water pump service.

Step1: Drain the Oil

Draining the oil from the gearbox should be the first step. Remove the drain stopper by unscrewing it with a big screwdriver. Please make sure you have a pan below to capture any excess oil. Remove the higher oil-level plug as well, in order to allow air to enter the transmission.

Step2: Remove Nuts

Take out all of the nuts that are keeping the lower section together. The majority of outboards have between four and seven nuts or bolts. If your socket does not fit, a ring wrench should be used instead. If the bottom unit is not in use, it should be removed. If not, you may need to give it a couple knocks with a gentle mallet to get it to move. Just be careful not to strike the cavitation plates on the flanges or they may shatter.

Step3: Slide off the Seal

The lower unit should be free of any nuts that are holding it on. There are four to seven nuts or bolts on the majority of outboard engines. If your socket does not fit, a ring wrench can be used for the socket in this situation.

If the lower unit is not in use, it should be taken out of service. Other than that, you may need to give it a couple of gentle hits with an oversized soft mallet. You must avoid hitting the flange cavitation plates, otherwise they may be damaged and broken.

Step4: Remove Pump Housing Bolts

To remove the bolts holding the pump housing in place, use a ring wrench to turn them counterclockwise. Alternatively, if the pump hasn’t been serviced recently, you may require the use of an impact wrench instead. Do not remove the bolts with an open-ended wrench under any circumstances. This is due to the fact that if you apply too much power on the bolt head, it is far more likely that the bolt head will shatter off, resulting in a completely different problem to deal with! Distinguish the two dwellings.

Make certain that the plate is removed.

Step5: Inspect the Impeller

All of the vanes on the impeller should be in good condition and parallel to one another. If they need to be replaced, now is the time to do it.

Step6: Clean Surfaces

Take the time to thoroughly clean all of the mating surfaces. This procedure assures that there will be no leaks. If there are big chunks of sealant or gasket that need to be removed, a sharp razor blade can be used to do this. Fine emery paper should be sufficient for cleaning up tiny impurities. When you’re finished, wipe it off with a clean towel to remove any remaining dust. Everything should be sparkling and brand new. After that, you may clean the inside of the pump housing. Gongs and score markers should be avoided at all costs.

Before reassembling everything, it is necessary to do a lower unit pressure test to see whether any of the seals are leaking.

Step7: Reassemble with New Parts

The impeller, seals, O-rings, and gaskets are all included in a water pump repair kit, so you won’t have to buy them separately. After everything has been cleaned, reassemble the system using the new parts. Apply a little amount of the gasket sealing compound and drop your gasket into position. Make certain that each and every hole is properly aligned. In addition, you’ll want to install a new key. This is located in the flat section of the shaft. If you are installing a new impeller, be sure that the key way in the hub corresponds to the key that was previously used.

This also serves to lubricate the pump for the first few seconds after the water enters the system.

Step8: Reassemble

As you lower the housing, ease it over the vanes while rotating the shaft in a clockwise direction to secure it. Because of this action, the blades are able to bend while the body of the pump is entirely supported by the base plate gasket. Replacing all of the bolts and tightening them until they are completely snug is critical. Pushing the new seal down until it is flush with the pump housing should be sufficient. In addition, the package should contain a setting tool, which you will use to press down on the top of the seal to fix it in place.

Not only will this spread everything out, but it will also ensure that there isn’t an excessive amount of compression. A tiny amount of engine spline coupling grease should be applied to the top of the drive shaft. Grease the gear-shift coupler with a little amount of petroleum jelly.

Step9: Refill Gearbox

Lower unit should be reinstalled once screw plugs have been replaced. Make sure you don’t overtighten any of the nut and bolt combinations. Fill the gearbox with the correct type of oil. Once the job is completed, you should test the parts, just like you would with any other servicing. Run your outboard motor while keeping a close eye on the stream of water. Everything should be up and running at this point. Here are a handful of films that demonstrate some of these techniques!

Check Us Out!

If you are experiencing symptoms of a failing outboard water pump, read this article to learn how to diagnose the problem. We want to make sure that everything with your outboard is functioning well, which is why we have a plethora of tips and techniques on our YouTube channel. Also available are blog entries that address a variety of needs, ranging from general upkeep to major repair work. With our assistance, you can make the most of your sailing experience.

How to Rebuild an Outboard Motor Water Pump

In case you’ve previously read the article 15 Outboard Motor Maintenance Blind Spots You Can’t Afford to Miss and determined that your outboard motor’s water pump (7) is one of your maintenance blind spots, then this piece is specifically designed for you. The information in this post is also useful if you didn’t read the previous article and don’t know how to maintain a water pump. In that piece, I recommended that you clean your cooling system on a regular basis to keep it from becoming clogged and to save wear on your water pump.

1. As previously said, I will demonstrate how to replace the impeller in a future article.
2. In the event that you only wish to repair the impeller, you may also utilize this page for that purpose; simply disregard the sections that discuss changing the other components.
3. You will normally have the option of purchasing either a single impeller (about $25) or a whole service kit (around $40).
4. Even though the impeller has been rebuilt in the past, there may be other wear inside the pump that has not yet been fixed, as you will see in the section that follows.

Water Pump Anatomy 101

In case you’ve previously read the article 15 Outboard Motor Maintenance Blind Spots You Can’t Afford to Miss and determined that your outboard motor’s water pump (7) is one of your maintenance blind spots, then this piece is specifically tailored for you. The information in this post is also useful if you did not read the previous article and do not know how to properly maintain a water pump. According to that article, you should clean your cooling system on a regular basis in order to avoid blockage and to decrease wear on your water pump.

In a future article, I’ll teach you how to replace the impeller, as I promised.

In the event that you only wish to repair the impeller, you may also utilize this page for that purpose; simply disregard the sections that discuss changing the other components.

Most of the time, you will be able to choose between purchasing only the impeller (which will cost around $25) or purchasing a whole service kit (which would cost approximately $40).

If this will be the first time that you have opened your water pump, I recommend that you get the kit instead. As you can see below, even though the impeller has been rebuilt in the past, there may be additional wear within the pump that has not yet been fixed.

Casualty of Wear

One of the water pump nuts snapped off in the midst of the film, which is visible in the middle of the movie. This was caused by galvanic corrosion. What I didn’t show in the video was me removing the damaged bolt from its socket. It turned out to be a remarkably successful endeavor. Because the bolt broke about 1/2′′ above the lower unit casing rather than flush with or below the mating surface, I was lucky that the damage was limited to the bottom unit casing. After gently prying the top plate away from the casing, I soaked a strip of paper towel in common vinegar and wrapped it around the exposed area of the bolt, allowing the vinegar to seep into the threads over time while the paper towel dried.

• Using vinegar to dissolve the aluminum oxide was an excellent solution for this problem.
• If you ever come across some galvanic corrosion, unless you’re a high-stakes gambler (or lady), go for the vinegar before things start to go wrong.
• That bolt will be added to my expanding Hall of Shame in the post titled “Beware of galvanic corrosion,” which will be published soon.
• Even more costly is the time spent away from the water while waiting for components to arrive and then replacing them.
• In the meanwhile, I was fortunate enough to have a buddy give me his spare masthead.
• Don’t forget about your own boat!
• You can simply locate exactly what you’re looking for and acquire the items you need fast and at a reasonable price.

This is the perfect gift for any frugal sailor.

There you have it – instructions on how to obtain the items you want and how to install them.

Avoid spending possibly hundreds of dollars on having someone else do it for you if you have the time and energy to do it yourself!

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Outboard water impeller, how often to change?

One of the water pump nuts fell off in the midst of the movie, which is visible in the middle of the video. Galvanic corrosion caused this to happen. My attempt to remove the fractured bolt was not included in the video. Honestly, it worked out very nicely in the end! Because the bolt broke approximately 1/2 inch above the lower unit casing rather than flush with or below the mating surface, I was lucky that the damage was limited to the bottom unit casing. Then, after gently prying the top plate away from the casing, I soaked a piece of paper towel in common vinegar and wrapped it around portion of the bolt that was exposed, allowing the vinegar to seep into the threads over time.

Using vinegar to dissolve the aluminum oxide was an excellent solution.

In the event that you come across some galvanic corrosion, go for the vinegar immediately, unless you’re a high-stakes gambler (or lady).

The post titled “Beware of galvanic corrosion” will have an entry for that bolt in my ever-expanding Hall of Shame.

However, the time lost from sailing while components are being ordered and installed is far more costly.

In the meanwhile, I was fortunate enough to have a buddy lend me his spare masthead.

Don’t forget to take care of your own vessel!

You can simply locate what you’re looking for and have the components delivered swiftly and at a reasonable price.

Any stingy sailor would appreciate this.

Those are the instructions on where to obtain the parts you require and how to install them.

Avoid spending possibly hundreds of dollars on having someone else do it for you if you have the time and energy to do it yourself.

Is it okay if I send you an email whenever I write an article like this one?

Along with the password to the Downloadspage, you will receive periodic emails with information and discounts that are only available to followers. Even though it is a completely free service, hardly no one takes use of it.

• It is possible to see where one of the water pump nuts snapped off in the middle of the video due to galvanic corrosion. What I didn’t show in the video was me removing the broken bolt from the machine. It worked out rather good, in fact. Because the bolt broke approximately 1/2′′ above the lower unit casing rather than flush with or below the mating surface, I was lucky that the damage was limited to the upper unit casing. After gently prying the top plate away from the casing, I soaked a piece of paper towel in regular vinegar and wrapped it over the exposed area of the bolt, allowing the vinegar to seep into the threads over time. Maintaining saturation allowed me to lock two nuts together on the exposed end of the bolt and back it out with ease after a few days. The vinegar performed admirably in dissolving the aluminum oxide. This approach would have likely worked even if the bolt had snapped off flush
• I would have simply had to drill into the bolt far enough to grab it with a bolt extractor rather than drilling into it flat. If you ever come across some galvanic corrosion, go for the vinegar immediately, unless you’re a high-rolling gambler (or lady). Three and a half bolts were removed without incident. That bolt will be added to my ever-expanding Hall of Shame in the essay headed “Beware of galvanic corrosion.” So far, galvanic corrosion has cost me around $100 in replacement components that have broken while attempting to dislodge seized fasteners. Even more costly is the time spent away from the water while waiting for components and then replacing them. I had to wait 15 weeks just to get a new masthead. Fortunately, a buddy was kind enough to lend me his spare masthead while I was waiting. If the former owner of Summer Dance had given more attention to corrosion prevention, it would have cost him significantly less than that, and it would have cost me nothing. Don’t forget to take care of your own boat! Before I conclude, I’d like to recommend Boats.net as a resource for outboard motor component schematics and replacement parts. You can simply locate exactly what you’re looking for and have the components delivered swiftly and at a reasonable price. They’re authorized dealers for Evinrude, Honda, Mercury, Suzuki, Tohatsu, and Yamaha products, among other brands. This is the ideal gift for any frugal sailor. I have no affiliation with them in any manner
• I simply enjoy their website. There you have it – instructions on how to obtain the items you want as well as how to install them. I hope this essay has provided you with a better understanding of how your outboard motor’s water pump operates and how simple it is to repair your outboard motor. If you’re willing to put in the effort, don’t waste hundreds of dollars hiring someone to do it for you
• Instead, do it yourself! Once this is accomplished, there will no longer be a maintenance blind spot as long as the rate of wear is monitored on an ongoing basis. Would you want to be alerted when I write more pieces like this? Please enter your your address here. Fill out the form below to subscribe to this blog and receive email alerts of new entries. You will also receive periodic newsletters that contain information and bargains that are only available to subscribers, as well as the password to the Downloads page. It’s completely free, and you may cancel at any moment, but nearly no one does.