.: Canals.....

Heres some maintenance tips for you....


.: Contents

Diesel engines

Most marine diesels will be old. Very old. If your engine isn't, then its probably a Kubota - (re badged as Nanni marine or Beta or some such) for a kubota - read 'BMC'. Anyway. your most likely problems are going to be 'ran it out of diesel' and 'it wont start'.

Poor starting is common, it can be many things, but as long as it CAN start, the following should get it going. Locate air filter, take it off and pour in a teaspoon and a half of oil. Get a blow lamp, or at a pinch a rag soaked in diesel on a stick, light it and hold it to the air intake while cranking. The oil will temporarily solve low compression, the flames will solve 'broken heater plugs' if it shows no signs of running, try repeating after doing the next bit.

If you have run the engine out of diesel, it will need to be bled, it wont pull diesel through from the tank by itself. You need to find the bleed valves on the injector pump and loosen them - on a pump that serves several cylinders there are two, on a pump that serves one cylinder there is one. Now these are open, pump the fuel lift pump manual handle. Be prepared to do this for a while. Initially you will get air, then diesel, then air again, then diesel....... then air, then finally a firm squirt of diesel - trust me, you can see when the primary lines are bled - its deceptive as it looks OK after the first time the air goes, but it wont be. Once you are happy that there is diesel to the pump, do the bleed nuts back up, and loosen all four injector pipes where they attach to the injectors. Put the throttle to full power, and crank the engine for 10-15 seconds. Wait 30 seconds and repeat. You should see the diesel start to squirt from the back of the loosened nut. Note - put your hand in the way of high pressure diesel and it will inject into your skin, you may then die. be warned. Now tighten up three of the four injection pipes and start as normal. Once the engine is heard to 'try' to start, tighten up the last one.


Your going to have either a 1500 BMC, 1800 BMC or 2.25 BMC, 1500 has the injector pump where the distributor should be, the 1800 has it alongside the block, and both have the normal 'Mini' rocker cover. The 2.25 is the same as a series 1 or 2 land rover. All need heat to start, 30 seconds minimum and 20 seconds post heat, (yes, that means keep the heaters going once the engine is running for 20 seconds to stop unburned diesel washing the oil off the bores). Starter motors on these engines are weak and bleeding the diesel through is tricky, these two factors combined are an issue.

If the head gasket goes on a BMC (symptoms are water in oil or oil in water or loss of coolant among others) - then don be scared of replacing it yourself - you cant really screw it up - there's no timing to deal with and you only need about 8 tools....... its not easy, but your not likely to make matters worse - a mechanic will pick up where you gave up without too much trouble. Link to the manual for 1.5 / 2.5 BMC is HERE its huge so takes ages to load - be patient.

The 1500 BMC has an element filter, in a metal housing. OMG, I good at this kind of thing but these are a proper pain. Consider getting a spin on filter housing to make life easier - sold by ASAP supplies. ASAP supplies list this for a Perkins 4108, but don worry - it fits - they call it an 'engineering fit' as far as i can see that just meant the original bolts off the old housing needed some washers adding as they are half an inch too long. I used the bush bit from a 15mm - 10mm plumbing adapter - looked nicer.


Ok, there's a few to choose from here - HR2 SR2 AVA2 AV2 PH2 TS2 TX2 AA2 AB2....... doesn't matter, all mostly the same. The main thing about a lister is it has separate injection pumps for each cylinder, this is useful as its easier to diagnose.

Hard to start - dribble a teaspoon of oil per cylinder into the air intake. This is actually in the lister manual. Improves compression. Alternatively, run a blow lamp in the air intake while cranking. Listers often have injector pumps inside the oil casings. This is not great as if they leak it dilutes the oil and the engine will be ruined. Watch for 'thin' oil or rising oil level. Compression ratios on a lister are fairly low, so if you get black smoke feel free to remove and clean the injectors with a wire brush - they wont be difficult to re seal.

A lot of listers don have oil filters. Consider taking off a crankcase inspection hatch and mopping out the sludge every few years - when you change the oil obviously!

If you have starting trouble, try 'spill port timing' - google it.


There are three types of cooling for marine engines - AIR, RAW and KEEL..... Its this simple - 'Raw' takes canal water, feeds it through the engine and out the exhaust to cool the engine, 'Keel' uses a captive circuit - like a car - and circulates it through the engine and tanks welded to the side of the hull that act like radiators, 'Air' is simply blown air. Before investigating the coolant circuit, check your oil level.

Raw - three things to look at (for a DIYer - there is more obviously) Find the raw water pump, its driven by a belt - like the alternator, except it has pipes not cables..... Obviously a slipping / missing belt will cause overheating. A damaged impeller can also be an issue - the back of the raw water pump can be removed to inspect (shut off the raw water valve first or you will sink) the impeller is a little rubber thing with flaps all round it. The flaps should be long enough to be touching the sides of the impeller housing, and not damaged. Get some spare impellers incase. The usual issue with raw is a blocked filter. There are sooo many types of filter that its difficult to describe. Follow the pipes from the raw water pump - one goes to the engine, one to the filter. Isolate the water, remove filter and check.

Keel - this system is the best for the health of the engine but can be a pain. The coolant is pumped by the normal water pump - belt driven same as alternator, but usually part of the engine unlike the raw type. Belts can be an issue, but more likely is low coolant level / air lock is more likely. Low coolant level is a pain because you wont know till the engine overheats, at which point you cannot remove the cap to refill! If a keel cooled engine overheats, initially try taking the engine out of gear, rev to 1200-1500 rpm (BMC) - fast idle for 20 seconds. The combination of no load and fast revs should force the coolant to circulate. If you don see the temperature drop quickly (within 30 seconds) shut down. This is only a temporary solution only, get to somewhere to moor, wait for it to cool and refill. When cold, refill and massage the rubber hoses to try to get out air.

Air - the usual situation is you 'smell' the engine overheating - burning oil etc - assuming your engine didn't overheat before, then repair is simple. Initially check the oil pressure gauge if you have one - if its fairly normal, then drop engine out of gear, rev engine to fast idle, for a minute, with engine hatch covers off. This should cool it. To find the source of the problem get hatches off the engine room, let engine cool and then inspect. An air cooled engine cools by blowing air through the cylinder fins from a fan. Usually the fan is on the flywheel. You initially need to check the path of the air - there will be an inlet and outlet grill for air - both must be clear of debris and the ducting connected - there will be an inlet or outlet duct or both. Most engines have an outlet duct - make sure its connected - its going to be a big duct (not a little pipe) a lot of boats have this missing, this means the engine tries to cool itself with hot air! so check for a complete air path - from fresh air to engine to outside. Assuming the problems not found then you need to look further - assuming engine is cold, start engine and 'feel' the airflow from the outlet duct (not exhaust) and see if its weak - if so, or even if not, inspect the fins on the flywheel or fan - often full of leaves...with engine off, clear out - watch your fingers. Note - the blades should be slightly curved - so scratch at the blades to make sure that they don just 'appear' ok - dirt in the 'curve' will stop the fan working. If that's ok, its crud on the cylinder fins - these can usually be accessed by taking off the outlet duct. Once you have located the fins, scrape off the oily crud - a hacksaw blade, a bit of coat hanger, a screwdriver - all good tools. Don be scared of using a hose pipe too - just make sure the engine is cool, the air inlet is covered and the water doesn't get into oil breather or dipstick. Its sometimes worth running the engine for 30 seconds at fast idle as you do this to blow out what you have scraped out (keep clear!)

Diesel bug

You will know when you have diesel bug. You will appear to run out of diesel.... with a full tank, I don't know where the stuff comes from, but I know how to get rid of it.

First thing - check your filters - do they seem to be full of black/brown mud? yup, that's diesel bug. You will need to get some biocide - try or any chandlery will have it - and dose the tank. Change your primary and secondary fuel filters, and buy four spare primary filters. Run as normal, but after the first 20 hours change your primary filter, then 20 later do the same thing. If your still getting noticeable brown mud, twice more.


Small leaks can be plugged with a sharpened willow twig, which will expand and seal the hole........ Apparently. Lets be fair, any twig will do. Ok, now there are two types of leak, irritating, and critical.

Irritating leaks are small leaks, and finding the source is tricky. Best policy is to slip the boat, and look for drips. However, If you can find the hole, there are several mix together putty's that set like steel which will do a great job in the short to medium term, mix and knead into the hole, then put something on top of it as it sets to keep the putty in the hole - heavy weight or the like. Consider also re ballasting the boat to expose the hole, (not too much, don't roll it over) and spot welding or using epoxy to seal it. Araldite is ok, fibre glass resin is also good. The definition of irritating is different for different people. I have a friend who has a 70ft narrowboat, moored at Kew bridge. The boat is made of two smaller ones welded together. He has a two foot split where the sides meet the bottom plate, 1/2" wide, this to him is irritating. He has packed it with car body filler and is quite happy. As its tidal the metal flexes a lot, so he regularly scrapes it out when the tide goes out and refills it. Hmmm.

Critical leaks are those that will sink you, either by constantly running the bilge pump, or by being to much for the pump. Leaks that constantly run the pump are smaller, often a big 'pinhole' - again try the putty, or in an emergency, carve a splinter of wood to fit and tap it gently into the hole (your boat has a hole, its not in good shape - be gentle!).

Big leaks are a problem, but are easier to find! split seams from hitting a rock are common, as are seams going through general corrosion. Your only hope of staying afloat if this happens is to pack cloth into the crack - grease, silicone or Vaseline will improve this, if you have any, as it waterproofs the cloth. This is not going to stop the leak but it may let you get to a slip way. Raw water inlets can get torn off sometimes and a lot of water can get in, this isn't so bad as you have solid metal around it - jam anything in you can!

Stern glands can leak, this often can be stopped by regular application of the greaser, if not - try nipping up your stern gland nuts. If not - repack it...... google it.

In any case, a leak suggests serious corrosion. be ready for over plating work!

Sinking - if you feel you are going to sink, and have a choice over where it occurs, try to get to the towpath side, run aground if you can find a shallow bit (that usually will give an end result of two inches less water in your boat), but never sink mid channel if you can help it. Other good sinking spots are, near a road, or at the edge of a marina. Both places where you can be refloated easily.

If you are unfortunate and sink, BW will re float you (and bill you later) they usually either install a massive pump to empty out the water, or insert a huge sausage into the cabin, and pump it full of water. If you have a choice go with the pump, as the sausage will blow out all your windows.


A boat fire is a terrible thing, even if its small its such an enclosed space the smoke gets into everything, be aware of this if you try to fight it yourself, especially if using CO2 fire extinguishers - there will be no air to breathe!

The aftermath of a fire is bad too, if the fire brigade haven't actually sunk you with water hoses, the whole place will be soaked, stinking and black. Any windows close by the blaze will have blown out, and most likely any plumbing or electrical systems wont now be working.

It now gets worse. Any steel - roof, windows surrounds, sides etc, that has been heated will have warped. Window surrounds are the worst - you actually have to cut slices into the window surrounds, pull the steel straight with clamps and weld it back, roofs will never be the same again, and even when the steel has been straightened, the metal has changed - doesn't matter what you do to it, rust bleeds through from under the paint and the steel is 'soft' and deforms easily in those areas. Tip - don't buy a burnt out boat.


Batteries need to be kept full of water, distilled is best, but in an emergency, soft water.....

The biggest danger with batteries is a short circuit. If you get a dead short across a bank of five leisure batteries, not only will you ruin them, you may get a fire and explosion. Personally i have a fused live and a fused neutral to my batteries. You should do this as if a stray wire hits a live terminal, you need to have a neutral fuse. This is something that happened to me - my stop cable snapped, and dropped onto the live terminal of the batteries. Within seconds i had a huge cloud of smoke, the cables were glowing red hot and the insulation was on fire. Luckily i knew what had just happened so i Pulled the stop cable away. You may not be so lucky.

Another battery 'issue' is the hydrogen they release when charging. I always felt this was a bit of a joke, and wasn't going to be at all dangerous, till I cut a corner off a support close to my batteries with a grinder. The picture above shows what happened. There was a massive bang and acid everywhere.

To make a battery last, you must not overcharge it, keep it topped up, not discharge it too quick, not overuse it, not discharge it too far, not charge it too quick, not leave it discharged, not get it too hot, not get it too cold, not shake it about, keep its terminals clean, And regularly equalise its charge.......... Do you get the picture?

No battery is going to last too long on a boat. It only takes an hours lapse in concentration to fully discharge a battery.............. And that's crippled its life span. Overcharge any sealed or low maintenance battery and you cannot refill it..... its as good as dead. Try to start your boat connected to your leisure batteries....... you will draw too many amps..... sooooo easy to ruin.

Pound for pound there are no longer lasting, more cost effective batteries than flooded wet cell. You will have to top up the cells with distilled water every month, but that's a minor issue.

There are many kinds of 'deep cycle battery, Some are branded 'multi purpose' - avoid - these are jumped up car batteries, it all comes down to weight, pure and simple, the more a battery weighs, the better it usually is, if one 110Ah is 20kg and another 110Ah if 15kg, you will probably find that the 15kg one has (lets put this nicely) - 'altered the way it reports its power'....... Deep cycle batteries have nice thick lead plates, which weigh a lot.

Lets just look at the different ways of describing a batteries power for a moment, deep cycle batteries will give different amounts of power over different times. Over 20 hours a battery may be able to offer up 110 Ah, but if you took it slower, that same battery can give more - say 150 Ah over 30 hours....... Tricky battery manufacturers may give the Ah rating over longer time - the standard is 'C20' or how much the battery will give if run flat in 20 hours. That's a bit complex. Consider this, if asked to move bricks up a hill, you might be able to get 100 up in a day. If given longer, a weaker person could do more. Doesn't make him more powerful. Same with batteries.

Battery warranties are lovely things.... They are 'Pro rated' ...... Ha! On a 5 year warranty what this usually means is that rather than being able to walk in and ask for a new one 2 years later, they will divide the purchase price by five, and give you back three fifths towards a new one - I.e. you have to buy a new battery! It doesn't really matter, the simple truth is this, 90% of the time, it will be your fault the battery is dead.

To monitor your batteries you will need a volt meter, ideally you need an accurate digital one, The reason being, a charged 12v lead acid battery is 12.6v, a fully discharged one is 12v, and you only ever want to drain your battery to a maximum of 80% - 12.1v......... Lets just look at how 'Noddy the narrow boat' uses his batteries..... he runs them till his inverter warning siren sounds - (little buzzer) telling him his battery voltage is (Usually) 10.5v..... He thinks this is fine, switches off and leaves the batteries overnight, and recharges them in the morning. NOT OK, you will get 50-100 cycles (recharges) like that, the siren is to tell you the INVERTER is going to get damaged, coincidentally the batteries are flat and half ruined. BTW, the batteries will start to sulphate up the instant they are left discharged.


If your inverter stops working, there are two possible reasons - you connected it the wrong way, or its broken.

If you connect an inverter the wrong way, it blows up. Even if its under warranty, you wont be covered, so you may as well open it up. Do this with the unit disconnected, or you will end up dead, be warned. Inside, if your lucky, there may be a handful of fuses, all blown. Get some and change them. Its worked for me several times.

A broken inverter under warranty should be taken back, one that isn't, should be opened to look at the internal fuses as above. Also look for loose wires. (more common than you think - boat vibrates a lot when engine running)

Sterling are a good make and cheaper than you think these days - try

Heres what kills inverters - crossing the live and neutral 12v wires, putting it in an unventilated area so it cant dissipate heat, putting it in an area that gets damp, getting it wet, using it too hard - (800w on a 600w inverter constantly)


Window are a proper pain, and leak or drip condensation onto your stuff....... All opening windows have a little channel at the bottom - inside - that has little vents outside, this is to catch the water that leaks into the window seals - make sure the vents are free of moss, use a straightened paperclip. Your usual spot for a leak is where the window frame meets the side of the boat - look for gaps and holes........ then add silicone!


Two types - mechanical and hydraulic. In either case, overheating and slipping are probably your most likely problems. In both cases, check the oil level, and reduce power. In most cases going at half speed will stop the box slipping temporarily - enough to get you where your going for sure.

Mechanical boxes tend to be noisier at idle or low revs and harder to shift gears than the hydraulic equivalent..... cheaper to by tho! A PRM 160 is a lovely smooth hydraulic box......... very nice box.... very expensive ... very heavy.... A PRM 120 is a manual box....... small, light, rattly, harder to shift...... sounds bad right? - not really - a PRM 120 is excellent value for money.... £250 gets a good used one...... A scrap PRM 160 is £250....

Black oil or silver streaks is bad - shows overheating and wear respectively.......

A box that wont drive the prop often can be a broken linkage not operating the gear lever, or don discount a broken drive plate - to check if its either of these take out the dipstick and see if anything is moving in the box at all. If it isn't then its drive plate failure. (The primary shaft should always be turning with the engine unless the drive plate is broken)

Quite a lot of boxes have a 'get you home' facility where the clutch plates can be tightened to keep you going for a little while - get out your manual!

Don be scared of removing the box, taking it home and working on it - there's only two shafts in it - you CAN screw it up, but with care you should be ok. You can often get a complete set of bearings for £20 from bearingman, or try .....

Packing gland

I hate this thing, for those of you not sure what this is - its the brass jobby that the propellor shaft passes through to exit the boat. If your still not sure, its the thing that always leaks into your bilge.

The principle of this thing is that the outer section compresses some rope to give a seal against the sides of the inner and the prop shaft. Hi tech solution!

The gland should give a drip every minute of two when under way, but not leak when stationary. HA! these really are a pig. Here are some issues - too loose and it leaks, too tight and it wears the propshaft. Also, and heres a tip, (I learnt this the hard way) if you put your boat back into the water and your gland is too tight the cutlass bearing will overheat and burn out....... The bearing is lubricated and cooled by water and it cant get in because its air locked by the packing.... my tip is to loosen the gland till you get some water, then nip back up. I was slipped to have a plate done, went back in, tootled off up the cut, bearing caught fire..... nice!

The only real 'diy' repair possible is to nip up the two bolts to slow a leak....

Good luck!