On Board with Mark Corke

How to Keep Your Boat Running Smoothly: A Guide to Changing Your Raw Water Pump Impeller

I know I have covered it before, but I recently changed the water pump impeller in my generator and thought it worth going over a few things.

When it comes to boat water pump impellers, there are a few key things you need to know. You don't need many tools, and any handy boat owner will likely have all that is needed. However, there is one tool that makes things more accessible, and that is the impeller puller. I have used a could of well-padded screwdrivers to lever the old impeller out. It works, but you need to be careful not to damage the pump housing, which is easy to do and will lead to leaks and, perhaps, a costly replacement pump.

I have two raw after pumps on Seaglass, one for the main propulsion engine and a second for the generator. Of the two, the generator is far and away the more difficult of the two to service. The generator engine is a three-cylinder Yanmar which will be familiar to many readers; they are used both as generator engines and the main motive power on smaller launches and sailboats. The best advice I can give you if you have one of these engines is to remove the pump for service. The cover plate faces away from the front of the engine and is almost impossible to service with removal. This may seem a bit drastic but believe me, it will be far faster in the end and will save your temper and most likely lose the tiny screws that hold the cover plate in place from ending up in the bilge, never being seen again.

THE PULLER IN USE.

 

One crucial aspect is the impeller puller, a tool specifically designed to remove the impeller from the water pump housing. This tool helps make changing an impeller much easier and more efficient.

Every engine and installation is different, so this is a general guide and refers to Yanmar engines in particular. You will need a few tools to change an impeller, including wrenches or socket sets, pliers, fallen wrenches, and the impeller puller. The first step is to locate the water pump housing on your boat's engine. Once located, you can remove any necessary parts or covers to access the impeller.

Carefully remove bolts or screws securing the water pump housing using your wrench or socket set. With the housing removed, use the correct size Allen wrench to remove the set screws that allow the cover plate to come off. Sometimes it is stuck in place, and the edge of a craft knife is a handy tool to break the seal between the gasket, plate, and pump housing.

 

With the impeller exposed, use the puller to withdraw the old impeller, then clean up the pump housing, removing any old gasket fragments. Some pumps have an O ring instead; if so, remove this and discard it.

Getting the new impeller in place can be challenging; my go-to method is to wrap a plastic cable tie around the blades, squashing them down so the impeller can be slid into place. Use dishwashing liquid or glycerin as a lubricant to help the impeller slide in. Once the impeller is half inserted, cut the cable tie off and push it in, ensuring the cut out on the boss or splines aligns with the spindle. When the impeller is well seated, the cover can be replaced using the new O ring or gasket that can with the kit.

AVAILABLE AT THE PHARMACY, GLYCERIN IS PERFECT AT HELPING SLIDE THE NEW IMPELLER INTO PLACE

Finally, reassemble any parts or covers that were removed earlier and secure them back into place using your wrench or socket set. Double-checking for proper installation before starting your boat's engine is always a good idea.

 

WITHOUT REMOVING THE PUMP, THOSE SETSCREWS ARE SO EASY TO LOSE IN THE BILGE! (note the black burn mark on the housing, likely the result of  overheating at some time in the past)

By understanding how an impeller puller works and having access to the necessary tools, changing a boat water pump impeller becomes a manageable task for any boat owner or enthusiast.

It's a gas! Outboard, that is

 

The new Mercury 5hp Propane FourStroke delivers no-hassle portability, reliability and convenience running on alternative clean-burning fuel – whether it’s powering aluminum boats, inflatables or sailboats.

With a large 7.5 cubic inch (123cc) displacement, the new 5hp FourStroke Propane outboard offers best-in-class power by delivering a true 5hp.

Starting at just 59.5 pounds (27.2 kilograms) the 5hp Propane FourStroke is light and easy to carry or transport. And you can run it on the same conventional propane you’re probably using in your backyard grill, so there’s no gasoline to haul with the engine. It’s also friendly to the environment with 30% lower exhaust emissions compared to gasoline.

With a safety-first approach, the outboard comes standard with a propane auto shut-off valve on the engine and in the fuel hose connector. The standard 6-foot (1.8-meter) fuel hose threads quickly and easily to the outboard and comes with a standard US POL connector on the tank side. A 20-pound (5 gallon) tank of conventional propane provides approximately 10 hours of boating at full throttle.

“This is Mercury’s first outboard to run on clean-burning propane fuel,” said Jim Hergert, Mercury’s category manager of outboards 60hp and lower. “Propane doesn’t degrade or contain ethanol, so you don’t need to worry about what type of fuel to run or how fresh it is. The pressurized fuel system eliminates priming, making the outboard easier to start, and the auto shut-off valves are there for safety.

“In short, it’s a very eco-friendly, easy-to-use, reliable and intuitive outboard.”

Starting is made easy with the manual choke, which enriches the fuel-to-air ratio for fast and reliable starts, particularly when the engine is cold. Auto decompression reduces the pull force when using the starter rope.

The 5hp Propane FourStroke sports an easy-to-reach shift lever on the engine and has six tilt positions with a shallow-water drive to set the outboard where you need it.

Sail Power

Sail Power models are designed for boaters who use a small outboard to pilot their sailboat. The Sail Power model is offered in 20-inch (508 mm) and 25-inch (635 mm) shaft lengths, and additional features include:

• 12 Volt, 4 Amp / 50-Watt alternator charging system with cable allows sailors to charge a battery to run electronics or lights
• Reverse-thrust exhaust relief and high-thrust propeller improves slow-speed handling and control

 

Installing an automatic fire extinguisher

 

Of all the things that scare boat owners the most, sinking is probably at the top of the list. But fire is no less of a threat. Indeed, a fire, even if you manage to put it out, can easily lead to a sinking. The first line of defense when it comes to preventing a fire on board is to make sure that all systems are correctly installed and that there is nothing that can turn a small problem into a large one. Normally a single factor alone will not cause a fire; they are most often started by a combination of factors.

Should the worst happen you need to slant the odds in your favor of putting a fire out. The best fire extinguisher is probably a frightened sailor with a bucket, but after that, it usually comes down to genuine fire extinguishers. Most boats have a few of these on board. There should be one in each cabin, visible and easily accessible so that it can be grabbed and used in a hurry; speed is of the essence here.

But what if the fire is in the engine space? You may not even realize you have a fire there until it is too late. Worse yet, opening the engine cover to see what’s going on is often a bad idea, as it feeds additional oxygen to the fire and may cause a flare-up. The ABYC recommends that engine fires be tackled without opening the engine cover or—in larger vessels—the door to the engine room. The cover or door maintains a physical barrier between you and the fire and restricts the amount of oxygen that can reach the flames. Often, sailboat builders thoughtfully install fire ports in the front of their engine boxes; a small plastic disc pops out, allowing you to deploy the nozzle of a fire extinguisher through the hole. This is very sensible, but is not necessarily the best solution.

Top of the tree is an automatic fire extinguisher system. In its simplest form, this senses the engine room temperature, and when it rises above a preset limit, deploys an inert gas to deprive the engine room of oxygen, thus putting out the fire. Halon used to be the gas of choice, but environmental concerns have resulted in it being outlawed. New systems use another gas called heptafluoropropane, although halon is still acceptable for existing systems. (If you do own a boat with a halon system, be aware that it cannot be refilled with halon when serviced; the same holds true for older refrigeration units that use halon as a refrigerant.)

Installing an automatic fire extinguisher in the engine room is well within the capabilities of a competent DIY owner, but it is necessary to do a little research first. I contacted Sea Fire, who supplied me with the necessary parts to complete the installation that you see here after sending me a worksheet that asked some questions about the boat, engine size, location and most important, the size of the space that the system would protect.

In theory, it is possible to install an automatic extinguisher that employs a vial on a sprinkler head at the top of the extinguisher cylinder, which bursts at a certain temperature and smothers the fire. The advantage to this approach is that you don’t have to make any extraneous connections to your engine room. Most owners, though, will opt for a slightly more sophisticated system, which is what I did. Connected to the top of the cylinder in my system is a cable release controlled by a handle next to the helm that can be pulled to deploy the extinguishing agent manually. Because the boat in which I was making the installation had a large electronically controlled engine, I also installed an automatic shut-down system. With this, if the extinguisher is deployed either manually or automatically a relay trips and shuts down the engine. Shutting down the engine if it is running ensures that the extinguishing agent will not be sucked into the engine and ejected out of the exhaust before it has the chance to do its job and put the fire out.

 

Here’s How I Did It

 

Tools required:

Drill, screwdrivers, pliers, tape measure, crimpers, wrenches

 

Skill level:

Advanced amateur

1 Decide where the extinguisher will go. In many cases the decision is made for you, as there is not much space in the average engine room. Bear in mind that you will have to make a connection to the top of the cylinder and that, depending on the type of system you have, the cylinder will either need to be mounted horizontally or vertically. This will be made clear in the installation instructions.

2 Measure carefully, then bolt the mounting bracket into position. I had a nice clear space on the aft bulkhead, which was just perfect. You may not be so lucky and may have to reroute wires or hoses if they are in the way.     

3 Mount the extinguisher as outlined in the instructions. The Sea Fire I’m mounting has stainless steel worm-drive clips that pass through the bracket and around the cylinder. Make sure they are tight.

 
 

Install the manual release cable. Bear in mind that it is stiff, like a throttle or gear shift cable, and will not bend in a tight radius. Cables are supplied in almost any length, so measure the run of the cable before ordering. An old piece of 6mm 1x19 rigging wire is handy for this, as it has the same bend characteristics as the release cable.

 

4A. After deciding where the cable will go, install the plate for the manual release, which should be near the helm. You will also need to drill a hole for the cable attachment; I was lucky to be able to use the plate to cover an unwanted hole where a gauge used to be mounted  

4B.Install the brass nut and washer before passing the end of the cable through the hole.

4C.Then install the other components on the other side: barrel nut, O ring, T handle, and safety clip.        Connect the other end of the cable to the cylinder, which is retained by a spring clip. It is also worth noting that the cylinder has a safety pin in place that has to be removed, but leave that until you have completed the installation to avoid a possible accidental discharge.    

 

5 Use a hole saw to drill a mounting hole for the monitor panel.

6 The panel is passed through the hole and secured by a straddle clip on the back.

 

7 Wiring is likely to be the most time-consuming part of the job, as it must be neat and well ordered. First mount the relay/control box. I put mine behind the breaker panel. Use cable of the correct gauge; Sea Fire recommends no smaller than 16 AWG.

1. The wiring is fairly easy to follow, but requires connections from the top of the cylinder, a power feed and connections to the electrical engine shut-down solenoid. When connecting a shut-down solenoid, be aware that the contacts will either be normally open or normally closed. You may need to refer to the engine wiring diagram to identify your specific application and which wire you need to splice into.
2. Install the CAT 5 Ethernet cable between the monitor panel and control box.
3. Make the power connections to the fuse box, which must be protected with the correct amperage fuse. Don’t forget to mark up the fuse for identification later.

Finally, clip back the cables for a neat and orderly appearance.

With thanks to Brewer South Freeport and Matt Durkin.

 

No mess fuel tank filling

 

You know the scenario, you head to the fuel dock to fill up with fuel before heading out, and believe that you will be able to control the inrush of fuel from the pump. You think that you'll be able to let go of the trigger in time, so that the fuel won't back up and spoil the decking. But once again you fail and then have to spend the next 20 minutes or so mopping up spilled diesel from the deck using almost an entire roll of paper towels in the process. No one likes to spill fuel, it smells bad, stains teak decking and any that gets in the water leaves a huge slick around the boat. Having owned both diesel and gasoline powered boats I have to say that diesel seems far worse in many ways than gas. Diesel has a predilection to foaming up and frothing all over the teak. The Clean Way Fuel Fill is in essence a baffled air vent which lets the fuel in and the air out. A snug fitting bung seals the fuel deck fill and any blow back foams up into the elongated funnel. Internal baffles prevent sploshing (is that a word?) and the clear plastic lets you easily see when the diesel starts to foam up, contained inside the plastic rather than all over your decks.

I'll admit that the shot above is clearly a publicity photo, but it does show rather well, the Clean Way Fuel Fill from Scanvik marine. I've been trying this out recently, as they rather graciously gave me one to try, and I have to admit that it does work, and work well. By the way there is a video on their website which shows it in action.

I can recommend the Clean Way, it does what it says, keeps the deck clean and prevents spills but there is another, cheaper, way. One trick I learned many years ago is that just before you fill up and remove the fuel filler cap, sloosh (another great word) a couple of buckets of seawater on the deck. Then, if any fuel does leak it will tend to float on top of the water and can be cleaned up far more easily than if it is allowed to soak into the teak or fiberglass.

Cleaning a sea strainer

 

Some readers were recently asking about cleaning a Groco sea strainer. There seems to be a little confusion, especially about the stainless basket which you need to pull out to properly clean the gunk out. Here's a short viddy I did for BoatU.S to walk you through the process.

Water heater Anode - part 2

A couple of posts back I wrote about replacing the anode in an on board hot water heater. I seem to have a struck a chord and as I thought many correspondents did not even know that they had an anode in their water heater. Interestingly many water heater manufacturers also keep fairly quiet about the need for replacement anodes on a fairly regular basis presumably because they can make more money selling water heaters than anodes. Unlike the anodes in engine heat exchangers, oil coolers and so forth the anodes in water heaters are magnesium not zinc. There is a lot of chatter on some of the internet forums where 'experts' are telling folks to use zinc which is incorrect. Every water heater that I have ever worked on has a aluminum as a common ingredient on there insides and zinc is too close to aluminum on the galvanic scale to do any good, magnesium is farther down the scale and is less noble than the aluminum which it protects.

 

Many boats are fitted with six gallon water heaters from the likes of Seaward (shown above) or Force Ten and so on. These compact oblong water heaters do sterling service but DO NOT come supplied with a sacrificial anode as standard so from the very moment that they are installed and filled with water they start to corrode from the insides out. The first thing to pack up is often the heating element and this is often the only indication that something amiss to the boat owner and a new water heater is soon required thereafter. Getting the heater out can be a real bear; often installed in the engine room there is frequently little space to spare. Thankfully there is an answer and that is that you can save yourself a big headache and a ton of cash by installing an anode. The six gallon heaters mentioned above have a drain valve which is great when the time comes to winterize the boat but this can be removed and an anode screwed in in it's place, literally a five minute job. The part number for this is 74556, a 4 inch anode which costs $20 or less from one of the many online retailers – far cheaper and a lot less hassle than having to change the entire water heater. The other benefit of this is that with the anode in place of the tap the anode has to be removed to drain the tank so you can see at a glance how much is eroded and replace it if it is more than 50% gone.

 

While on the subject of anode protection I changed the pencil anode in the engine heat exchanger last weekend and after 100 hours of running you it's not hard to tell the old from the new replacement. This anode cost me $16 from Boatzincs who offer a vast array of zincs to suit almost any application. Cheap insurance I'd say and if you thought I was whining on a bit about the cost of a replacement water heater I would hate to even contemplate the cost of replacement engine parts if replacing this anode were overlooked.

 

Two or Four stroke

 

 

 

Outboard motors are everywhere and there can be few boaters who have not operated a boat with an outboard motor at some time. Even if you generally cruise in a larger boat which has an inboard engine or sails as the main means of propulsion there is a good chance that the dinghy that you use to get to the dock will have a small outboard on the back. In their simplest form an out board motor is a completely self contained unit that clamps onto the back or a small craft albeit an inflatable or rigid tender. Rumor has it that the outboard was invented by a young man called Ole Evinrude over 100 years ago. Others may dispute this claim and cite that it was actually a Frenchman who demonstrated an electric outboard some 15 years previously. Whatever the true story is there is no doubt that outboards have been a round for a very long time now and have become a very common sight. Almost any marina or boatyard is full of Evinrude, Mercury, Yamaha, Honda and many of the other common names.

 

Outboards come in a range of horsepower ratings, from small 2.5 hp motors weighing in the region of 20 pounds to large 300 hp behemoths capable of propelling large boats are breathtaking speeds.

 

While it is possible to buy electric and even propane fueled outboards by far the majority of outboard engines are fueled by gasoline. Gasoline outboards fall into two categories either two stroke or four stoke. Broadly speaking the main difference between a two stroke and four stoke is that with a two stroke oil is mixed with the gasoline and this lubricates the engine moving parts before it is burnt in the cylinder(S). With a four stroke motor, which is the type that you have in your car oil is contained in a sump or the lower half of the engine and remains in the engine and is not burnt and thus requires oil changes when the motor is serviced. Other significant differences are that with a two stroke motor every complete revolution of the engine is a power stroke as opposed to a four stoke where only every other complete revolution is a power stroke. Four stoke motors are also slightly more complex, have more moving parts and tend to be heavier than a two stroke motor of a similar horse power rating but this is changing and in truth with today’s motors this is less of an issue. Another difference is that four strokes tend to be quieter and slightly smoother in operation.

 

The big four in the outboard world are Honda, Yamaha, Mercury and Evinrude. Of these only Honda does not make two strokes. Yamaha offer the V Max V 6 two stroke engines in 150 and 175 hp outputs but offers no other 2 stokes, in the US at least. Evinrude on the other hand are fully committed to 2 stokes and offer the very popular rage of E-Tec motors but they do use four stroke motors for their smaller portable units.

So this begs the question, which type is right for you? It all depends. Normally the maximum or recommended output for use on your particular boat will be specified by the manufacturer of your vessel. Then you should compare engines from each of the motor manufacturers which fall into the size as recommended by the boat builder. Compare specifications, is there a dealer network in your particular area that can not only sell you the engine but who can service it for you after the sale. Talk to other owners and get their opinions. Search the web forums and see what others are saying about an engine you may be considering. Some of the smaller lakes do not allow 2 stroke motors so that may also factor into your thinking. If you can get a trial of any engine you are considering buying, most of the major manufacturers all have a strong presence at boat shows and can often arrange for you to see the motor actually operating. Finally not least is price; an outboard represents a significant outlay so shop around for the best deal. The fact is that I believe there is little to choose between modern two and four stoke motors. Long gone are the days of hard to start engines that oiled their plugs at the drop of a hat. Today's motors are long lasting reliable and will last for many years if properly maintained.

 

 

As a generally rule if you want fast acceleration and the most power from the lightest weight possible then opt for the two stroke. If on the other hand you want the quietest possible motor and are less concerned with out and out performance a four stoke may suit your needs better.

Racor fuel filters

Racor filters have become so synonymous with fuel filtration that the word Racors has almost become a generic term for filters. On recreational boats the 500 series are the most common and these are often fitted to both sail and power vessels. These area turbine style filter with the element sitting on top of a clear bowl. Fuel passes through the turbine where large bits of dirt and water are deposited in the bottom of the bowl then fuel travels through the paper element where any other debris is picked up. Racors are designed as primary filters, in other words fuel should pass through a further secondary filter before reaching the injector pump. Racors in concert with all other fuel filters are measured in terms of microns, the smaller the number the smaller the particles that are trapped by the filter. Typically these are 2,10 or 20 micron sizes filters. The actual size of the filter is the same so any one of the above filters will fit into the same housing it all depends on the amount of filtration required. A 2 micron filter may be better at cleaning the fuel but it will tend to clog faster especially if the fuel in the tank is less than perfect, on the other hand a 20 micron filter will tend to let larger particles through thus clogging the secondary filters sooner. I tend to use 10 micron filters in my Racor and 2 micron filters in my secondary fuel filter bowl and this seems to work well for me. As you will see in the first of the pictures at the top of this page a fair bit of sludge has collected in the bowl although this is actually the filter off the generator. Even so you can see the amount of muck that is kept out of the engine, a good thing. The lower picture is included which shows the bottom of the filter element, on the left is the old style element and on the right the newer style that Racor have recently introduced. With the old style it was necessary to slip on a spacer to the center post of the element holder, this sometimes used to get stuck and was hard to remove especially when the placement of the filter housing is in less than a perfect location. The new filter style has an extended sleeve as can be seen and this negates the requirement for the black spacer, an altogether far better arrangement.

One engine or two?

One of the never ending questions whenever power boaters get together is the thorny question of whether a boat should have one engine or two. There are arguments for both of course. Owners of twin screw boats will tell you that with two engines you have a spare if one should break down and that maneuvering in close quarters is easier. Owners of single engined craft will argue that only having one engine is simpler, you don't have to buy two of everything, there is more room in the engine room and if you are a skilled boat handler you should be able to dock a boat just fine with only one engine. 

For the last forty years I have only ever owned a boat with only one engine, true most of those boats have also had sails as auxiliary power if the engine were to fail but I have never as yet had a an engine that would not start and left me stranded. There have been times when I have sailed off the mooring and gone considerable distances without ever turning on the iron topsail and even come along side all under sail mostly for the smugness factor but I was fairly confident that the engine was there and would start if I ever needed it. The proponents of the two engine approach will often drive considerable distances in their cars with only one engine with nary a thought of what might happen if things go awry but in truth motors whether they be in cars or boats are pretty reliable. There will always be times when unexpected things happen and the engine might break down but these are generally pretty rare and it seems that a straw poll of some Boat US and Seatow guys that I know often say that they get calls out not because the engine has actually broken down but because the owner has run out of gas or has left the stereo on to long and flattened the battery.

I have operated my fair share of twin engined boats and I will agree that these can be easier to operate around the docks but having an engine costing 30 grand just to make things a bit easier around the docks is going a bit overboard if you will pardon the pun.

A 40 foot Nordhavn has completed a 24000 mile journey around the globe on one engine without it appears any sort of major mechanical mishap. Testament if ever there was one to the suitability of long distance power voyaging on one engine.  

Most engine failures can almost always be attributed to poor maintenance, providing that a diesel engine gets a clean supply of fuel, regular oil changes, cooling water and a goodly supply of clean air it will run for years. 

I used to work for the BBC many years ago and the transport department had what they called a twenty two and half mile an hour agreement. This meant that the average speed of any of the trucks was calculated to be twenty two and half miles per hour over the life of the truck. This figure was calculated allowing for time that the truck would be stuck in traffic, running on congested streets and the open road. It worked out pretty accurately. Therefore if we interpolate this to the average cruising boat with say 1500 hours on the engine that works out to a measly 33,750 road miles. For a diesel engine this is nothing and is just about run in.

Most boat engines be they diesel or gas rarely wear out most rust away from lack of use. 

So although I have not settled the debate as to one or two engines I am firmly down on the side of the single engine camp. For my money it is favorite for one thing there is more room in the engine room and thus maintenance is easier and more likely to be completed correctly and as Nordhavn have proved a single engine is perfectly capable of safe long trips and I don't expect they worried to much about not having that second engine as they pulled into the docks at Dana Point marina!

 

Torqeedo 40hp

Electric propulsion is nothng new, it has been around for more than one hundred years. What has always held it back has been the battery technology. Batteries are heavy, expensive and the slow rate of charge has been a bit of deterent to the slow adoption by the recreational boat market. This morning I got to go out for a ride on a center console boat equipped with the 40hp Torqeedo motor. The battery is a single Lithium Ion item which in this case is situated under the center console seat and console. Weighing in at 328 pounds it is something of a beast but it is diguised well and frankly you would never know it is there. In fact much of the space that would be taken up with the gas tank on a regular boat is in fact used for the battery stowage. The outboard itself operates on a voltage of 345 volts which is high but this keeps the battery cables to the motor to a sensible size. Anyone who has a 12 volt bow thruster on their boat will know just how thick the cables have to be for even a modest thruster of 3 or 4 horse power. If you remember your high school physics then you will remember that as voltage increases resistance decreases and so this is one reason for the high operating voltage, potential power from the battery is made into tractive force rather than heat in the form of electrical resistance. So just how does the motor perform? The answer is very well. At first the quiet is unnerving. After turning on the key switch which is akin to an ignition switch on a regular gas engine nothing happens. All that you have done is energize the circuits and it is only as you push the 'throttle' control forward that electricity is sent to the motor and the boat starts to move forward. The lack of noise is uncanny and normal speech is possible even when driving the boat at 20 knots or so. Top speed as tested was around the 26 knot mark and even at that speed the only thing that you can hear is the whine of the reduction gear which on a gas engine is still present but masked by the motor. The brushless motor produces prodigious amounts of torgue and acelleration is swift. The down side to this installation is cost, the motor and battery as tested costs $35,000 which is significant. Although built to a high standards using the best German engineering there is no getting away from the cost, for the same money I can buy a Toyota Prius which has a hybrid power unit, batteries and all the other trimmings, and still have change left. If only Torqeedo can bring the price down of the motor and batteries they are onto a winner.