Diesel Engine Maintenance

I am on to my next Coastguard course now… Inboard Engine Maintenance. So once again I am going to be using the blog as a convenient place for me to store my study notes for my future reference. How engines work is a complete mystery to me, however I am super keen to learn! So here goes!

I have read the text book and translated in to notes for me to understand! If you are interested in diesel engines, then by all means have a good read of this post – sorry it is pretty long and lots of words and not many pictures. If you aren’t too keen on that you can go check out some of the other cool pages on my blog instead – like finding out how much I love seagulls…!

If you can’t do a Coastguard course, then I highly recommend purchasing a book by Nigel Calder called Boat Owners Mechanical & Electrical Manual. This is a bible for all on board systems. Every boat owner needs this book on board!


Why are Diesel engines used extensively in Marine applications?

  • They have low running costs
  • They are safe – a minimal risk of a fuel fire – unlike petrol. Diesel has a low flash point.
  • They are reliable (if you look after them!)
  • They perform well under a constant load

How it all works

Diesel fuel and air are mixed up in a cylinder – a fine spray of fuel is pumped under high pressure in to the cylinder. This atomised fuel mixes with the air in the cylinder and then compressed by the piston until combustion takes place. This then forces the piston back down which provides power to turn the crankshaft and then the propeller.

4 Stroke Operation:

  1. Intake Stroke – The inlet valve opens, the piston travels down and air is sucked in the cylinder
  2. Compression Stroke – The valves close, the piston travels up compressing the air in the cylinder
  3. Power Stroke – when the piston is at the top of the cylinder the air is fully compressed and is really hot – diesel fuel is then sprayed into the cylinder under very high pressure causing combustion. This forces the piston down and provides power to the driveshaft
  4. Exhaust Stroke – the piston moves up again and the exhaust valve opens and the gases are pushed out of the cylinder

Lubrication System:

An engine with insufficient oil or the wrong type of oil will quickly suffer catastrophic failure! (Gulp – sounds expensive!!!)

Engine and Gearbox oil performs three functions

  1. lubrication
  2. cooling
  3. cleaning – preventing wear
  • The Sump is a large chamber in the bottom of the engine where the oil is taken from and drained back in to
  • Oil Pick-Up – oil is sucked through a mesh covered pickup positioned low in the sump
  • Oil Filter – removes small bits of metal and debris to ensure that only clean oil is used to lubricate the engine
  • Oil Pump – pumps the oil up from the sump through the oil filter and on to the engine
  • Pressure Relief Valve – Maintains the oil pressure at a set level within the system
  • Oil Pressure Switch – If the oil pressure drops below normal, this switch triggers an alarm or light
  • Oil Cooler – larger engines over 50hp have this
  • Engine – oil is piped to internal parts of the engine that need lubricating – bearings, cylinder walls, pistons and cam shaft etc

You should check the oil on a regular basis (oops I don’t!) top up if required and change the oil and filters regularly – refer to your manual. This ensures a long life for your engine. Keep a close eye on any warning lights – the engine can be damaged very quickly if the lubrication system fails. (Eeek!)

When you are checking the oil level you should also check the colour and condition of the oil. You check the oil using the dipstick. (I know where that is!)

  • Jet black = normal
  • Greyish white = water contamination
  • Oil running quickly off the dipstick – may indicate diesel contamination in the oil.

You should check the type and grade of oil for your motor in your engine manual. Oil is classified by its thickness – viscosity – and its ability to cope with different temperatures and suitability for different engine types.

You will have engine oil and gear box oil. You should check both. The gear box  should use very little oil, so if the level falls then you may have a leak. (not good)

Keep your engine bay clean so that any leaks will be immediately apparent.

Use Marine Grease on other parts of the boat – like the propeller. Do not use graphite grease – it reacts with seawater and becomes very corrosive!

Fuel System

As mentioned before the fuel is injected in to the cylinder as a fine spray and it mixes with the air in the cylinder. It is essential that the fuel is very clean, free from water and dirt.

  1. Fuel Tank – fuel is sucked from the tank to the engine via fuel lines. It is important that the fuel lines are well protected and secured so that they don’t rub and get damaged. Check that the tank is well secured and the fittings are all tight.
  2. Fuel Valve – at the fuel tank there is a tap or valve that can be closed to prevent fuel leaving the tank in the case of a fire or for maintenance
  3. Debug filter – a magnetic fuel treatment unit – this may be used to combat the diesel bug problem (Oh really! I have had diesel bug and its awful. I haven’t heard about this system. Will do some research!)
  4. Primary – Racor Filter – Traps dirt and water. Not all fuel is clean and condensation can form in the tank. This filter stops dirt and water getting in to the engine. The water is heavier than the diesel so it sinks to the bottom of this filter and you can drain any sludge out of the bottom of the glass bowl by undoing the screw.
  5. Lift Pump – Fuel tanks are generally located low in the boat, so a pump is required to lift the fuel up to the engine. The engine operates this mechanically, but there is also a priming lever used to pump through the system manually. (I went for ages thinking my lift pump was broken, but I wasn’t pressing it down far enough…!)
  6. Secondary Filter – This is normally found on the side of the engine block and removes very fine particles from the fuel. It is usually a canister/cartridge and is usually changed when you change your oil. Carry spares.
  7. Injection Pump – This pump provides measured amounts of fuel at high pressure to the injectors. They are not owner serviceable as they are very technical bits!
  8. Injectors – They spray measured amounts of fuel in to the cylinders like an aerosol spray. Any excess fuel is used to cool the injectors and then that fuel is returned to the tank via the:
  9. Return Line – the fuel in here can be very hot and may raise the temperature of the fuel in the tank.

Always make sure you have enough fuel! A good rule of thumb is 1/3 to get there, 1/3 to get back and 1/3 for an emergency.

Fuel tanks have a breather or vent to allow air in to the tank as the fuel is used. If that gets blocked then it can starve the engine of fuel. It is usually a pipe which rises high enough so that any water getting in to the boat won’t go in there and there might also be a 180 degree bend at the top or a hood to also prevent water going in.

You must have clean fuel – take care where you get your fuel from, what it is stored in and for how long. Check and change your filters regularly (I can vouch for this – having had the diesel bug in my tank – a REAL hassle!) Keep your tanks filled up to prevent condensation.

Diesel bug is micro organisims growing in your fuel system. The technical names are Cladosporium resinae and Aspergillus fumigatus. It can form quickly in warm climates. It grows between the fuel and any water in the fuel tank. This forms a slime which can block filters, lines and injectors. This can cause engine failure at any time. It is also very corrosive – inside the pumps and injectors for example, which can cause leakage in to the oil system. This can cause crankshaft, bearing or other failures (eeek disgusting!)

You can prevent the bug by keeping your tank full to avoid condensation. You can also add biocide or one of the magnetic systems mentioned above. The bug can be identified by a rusty or cloudy colour, or slime, black coating in the fuel filter.

Air System

Air is required for the combustion process & for the fuel to be burnt efficiently. Naturally aspirated engines suck the air in through the filter as the piston moves down through the cylinder.

Any restriction of air coming in to the engine – blocked air filter, or an air tight engine compartment, will reduce power. Turbochargers actually force air under pressure in to the cylinders. This provides more air and then more power!

You should replace your air filters as part of your routine maintenance programme.


Marine exhausts can be either wet or dry. Some larger boats have their exhaust directed through a vertical exhaust pipe (funnel) in to the air, but most have a wet exhaust system near the engine and it exits at the stern of the boat. This process cools the exhaust gases and reduces the noise.

  1. Sea water is sucked in to the engine, and is mixed with the very hot exhaust gas in the bend called the mixing elbow. This is normally located just above the engine. Te water turns to steam and in the process reduces the temperature of the exhaust gas and muffles the sound.
  2. The steam condenses back in to water in the water lock and is expelled outside by the force of the exhaust gases. You don’t want any water coming back in to the engine!
  3. Some boats have a swan neck or bend in the system which is high above the waterline. This prevents sea water from coming in the exhaust when the engine isn’t running.

Warning: When you start an engine, water will still be injected in the exhaust. If the motor doesn’t start then the sea water will build up and may enter the cylinders if you persistently turn it over…

Exhaust colour and what it means…

  • Black – un-burnt fuel – black smoke is normally an air supply problem. Check your filter or ventilation to the engine compartment. There could be a damaged exhaust system, or faulty injectors
  • Blue – burning engine oil – get a mechanic!
  • Grey/White – a valve timing problem – get a mechanic!

Cooling System

Diesel engines run very hot and a cooling system is required to remove the heat. A Direct Water Cooling System pumps sea water around the engine before sending it back overboard.

  1. It comes in to the boat through a filter & possibly another strainer – there might also be a seacock on this water intake – make sure it is open before you start the motor!
  2. The water pump sucks the water in and around the engine – this is where the impeller lives!
  3. Thermostat – this regulated the amount of water flowing through the engine and keeps it at the correct temperature
  4. The water cools the engine as it moves around the channels and waterways inside the engine block & cylinder head
  5. Then it goes in to the exhaust system at the mixing elbow
  6. It exits the boat via the exhaust pipe with the exhaust gases.

The water pump has a flexible impeller inside. This rotates around creating the water flow. It is usually found on the front of the engine and is driven by a belt. Carry a spare belt and impeller in your spares kit!

If your engine over heats – you should check your water pump belt, impeller and water strainer (where the water comes in to the engine)

The thermostat is a heat sensitive valve. The amount of water flowing around the system is controlled by the thermostat opening and closing the valve. As the temperature heats up, the thermostat gradually opens and allows more water to flow through the system. Keep a spare thermostat on board in case your one jams open or shut. If it jams open, the engine will run cooler than normal, which gives less power, burns more fuel and may produce black smoke from the exhaust. You might not notice this immediately so keep an eye on the temperature gauge.

If it jams shut then the engine can overheat and cause serious damage. Your engine should have an overheating alarm to alert you. Never run your engine if it is overheating!

You can test a thermostat by heating it in a saucepan of water. The thermostat should be fully open just before the water boils. If it jams closed while you are at sea – a get you home solution is to temporarily remove the thermostat (wow cool!)

Make sure that you only use stainless steel hose clamps on any hoses running sea water. Some clams are just coated in stainless steel. If your hoses come off then you can get serious flooding or sink the boat if you don’t notice! (crikey! I am checking my hoses tomorrow!!)

Indirect fresh water cooling systems use a closed loop of fresh water to cool the engine. This is similar to how cars work. Fresh water is pumped around the engine, passing through the cylinder head and engine block. The hot water is then cooled in a heat exchanger using cold sea water. The sea water flows through tubes in the heat exchanger, and the hot fresh water flows around those tubes. The sea water and the fresh water are physically separated in different tubes. These systems are good as corrosive sea water doesn’t enter the engine.

The fresh water should also have antifreeze added as it raises the boiling point and reduces the risk of it freezing in cold weather.


High performance diesel engines have turbochargers to force air in to the cylinders. They use the exhaust gases to drive them. They also have after coolers – to cool the compressed air before it is delivered to the cylinders.

Electrical System

When you operate the ignition switch, it activates a solenoid that in turn connects the battery directly to the starter motor via a low power circuit. Thick cables are required to carry the high current from the battery to the starter motor.

The solenoid is a heavy duty switch which closes heavy duty contacts to complete the circuit from the battery to the starter motor.

The altenator generates electricity that is used to charge the batteries whenever the engine is running. It is normally run by a drive belt powered from the crank shaft.

Some engines have glow plugs that heat the air in the cylinder prior to starting the engine. There are a number of pre-heat systems so check your owners manual. You either have to turn the ignition to the glow plug position and wait for a set time period or until the light goes out before starting.

You normally stop the engine by shutting off the fuel at the injection pump. A manual shut off lever may be used on smaller engines or a solenoid on larger engines.

The battery master switch either isolates or connects the batteries to all the circuits. There are a variety if different batteries:

  • Lead Acid – lead plates submerged in an acid (electrolyte) solution
  • Gel – the acid solution is solidified with silica gel
  • AGM – absorbed glass matt.

Boats all have different power requirements. Engine starting & Domestic – lighting, sounders, fridges, radar, stereo etc. the size and number of batteries will depend on the amount of electrical equipment fitted.

Different capabilities are required to meet these needs:

  • Start battery – must be capable of delivering a high current for a short period of time. This needs high CCA – or Cold Cranking Amps
  • Deep Cycle Battery – must be capable of delivering a steady current for a long period of time for domestic requirements. Hit needs a high amp hour capacity
  • Dual Purpose Battery – this is a compromise between both.

Some boats might also have another battery located forward to power bow thrusters or the windlass.

You should try to run your batteries isolated. Don’t run them parallel except in an emergency, so you don’t run them both down. (whoops I do this!)

Common battery terms:

  • Volt (V) – the unit of measure for electrical potential
  • Ampere (Amp) – the electrical current passing through a circuit
  • Watt (W) – the unit of measuring electrical power – Watts = Amps x Volts
  • Capacity – the ability for a battery to deliver a specific quantity of electricity – described as Amp Hours
  • Amp-hour – A unit of measure for a battery’s electrical storage capacity, obtained by multiplying the current in amps by the time in hours of discharge. (a 100 Amp-hour capacity battery will deliver 5 amps for 20 hours or 1 amp for 100 hours)
  • Cold Cranking Performance (CCP) the discharge load measured in Amps which a new, fully charged battery can deliver continuously for 30 seconds while maintaining at least 1.2 volts per cell. This is displayed on the battery label
  • Self discharge – new and fully charged batteries will self discharge over time. This is caused by impurities in the battery or dampness on top allowing the currents to pass through. This can be 3-4% per month or up to 20% over six months. Recharge regularly – especially if shore power is available.

To maximise the life of batteries, keep them fully charged and topped up with electrolyte. – This should be just over the plates. Battery shops can check battery health, and a digital volt meter can also be used. A healthy fully charged battery should read 11.6 – 11.8 volts. A battery in poor condition will show less voltage. (good to know!)

Electrical systems usually have fuses or circuit breakers to protect equipment and wiring in the event of a short circuit or overloading. You should always carry spare fuses on board.

Check your wiring & connections regularly for corrosion. If they are green or corroded, remove and clean them and firmly tighten up again. Smear with non graphite grease. Wiring might need to be replaced if the corrosion is eating its way up inside the wire.

Galvanic corrosion occurs when two different metals are touching one another or are connected by sea water.

Anodes made of zinc are the most reactive of metals and are the first to dissolve. This makes zinc suitable for protecting engine parts against corrosion. Sacrificial anodes are placed below the waterline to protect the propeller and other exposed metal parts from corrosion. These anodes are also screwed inside the engine. Once it has been eaten down to 1/3 of its original size (2/3 eroded) then it must be replaced. Do not paint anodes.

Control Systems

Throttle and gear box systems vary. There are cable, hydraulic and electronic control systems. Cable systems are most common. They can either be a single lever operating both the throttle & gearbox, or separate controls operating independently.

Control cables consist of a strong outer sheath and an inner rod or very stiff single strand of wire. Operating the lever enables you to push or pill the control to which the cable is attached. Control cables can be extended and greased using marine grease – do not use CRC.

Gear Boxes

There are hydraulic, and mechanical (or crash) gear boxes. There are three gears – forward, neutral and reverse. Gear selection is usually operated by a push/pull control cable.

If your cable falls off, then you can select the gear you need by manually moving the gear shift on the gear box.

If you have a hydraulic gear box then the hydraulic fluid needs to be checked, on mechanical gear boxes they have oil and this must be checked before the engine is started.


There are many different types and styles of propeller. Matching the right one to your engine is essential. Always follow the recommendation of the engine or boat manufacturer.

Check your propeller regularly to make sure that the blades are not bent or chipped. Unusual vibrations might indicated propeller damage. When replacing a propeller on to a splined shaft, grease with marine grease, but never grease a tapered and keyed shaft.

Stern Glands

A stern gland allows the shaft to rotate freely without letting water in to the boat where the shaft exits the hull. there are many stern gland systems, so find out what kind you have and check the manual for recommended maintenance

A stuffing box is one common kind of stern gland. A tube fitted around the propeller shaft contains rings of grease impregnated packing. An adjustable compression sleeve holds the packing in place and can be tightened so that the packing makes an almost watertight seal around the shaft. If it is too tight, friction will dry out the grease and wear away the packing. If it is too loose it will let excessive amounts of water in to the boat. They can be repacked if required.


A coupling connects the gear box to the propeller shaft. Check for wear and damage and make sure that the bolts are all tight. They can be rigid or flexible.

General Notes

If you have a new motor it will require running in – check with the manufacturer for more details.

Loud Exhaust noise could indicate that there is a blockage with no water coming through the cooling system.

Get used to your engine noise, and keep the compartment clean so you can tell if there are any problems.

Reduce the risk of fires by: Not smoking or naked flames near batteries or near the engine, clean up oil and fuel spills, remove oily rags and paper from around the engine. Store flammable liquids away from the engine compartment.

Basic Checks


  • Check that you have enough fuel for your trip plus 1/3 spare
  • Check the propeller is clear of any debris – no ropes dangling over the side etc
  • If you have a bilge blower – turn it on for a few minutes to make sure that no fumes have accumulated in the bilge
  • Check your steering by turning it from one side to the other to make sure it is free from obstructions
  • If your boat has a stern gland – turn the greaser one turn
  • Do a quick visual check of the bilge for any fuel or water leaks
  • Check the engine & gear box oil and refill if necessary
  • Open sea cocks if required
  • Make sure there is enough fuel in the tank and ensure the tank is turned on
  • Make sure that your exhaust shut off valve is open
  • Turn on the batteries
  • Turn the key to heat the glow plugs if fitted.
  • Ensure the engine is in neutral and fast idle – 1000rpm
  • Start the engine

Post Start

  • Check the oil pressure light goes out
  • Check there is water coming from the exhaust
  • Check the batteries are charging
  • Allow the engine to warm up at fast idle for 20 minutes or until normal operating temperature is reached.

Stopping the engine

  • Put the throttle in neutral
  • Let it idle for a few minutes to cool down
  • Pull the shut down lever
  • Turn off the key

After the engine has stopped

  • Shut off the fuel tank fuel cock (I never do this!?)
  • Shut off the raw water sea cock
  • Turn off the battery master switch
  • Top up the fuel if required

Routine Maintenance

Spares & Tools

  • Oil for engine & gear box
  • Drive belts for all equipment
  • Impeller
  • Coolant additive (if required)
  • Thermostat
  • Fuel filters
  • Air filter
  • Oil filter
  • Marine grease (not graphite!)
  • Distilled water for batteries
  • Petroleum jelly or similar for battery terminals
  • Fuses

Fuel System

  • Keep the tanks filled up to prevent diesel bug. Use an additive when refuelling
  • Inspect fuel filters and change as per manufacturers guidelines (every 25 – 50 hours)
  • Turn off the fuel at the tank
  • Bleed the air from the system
  • Check all fuel lines for leaks or damage
  • Feel injectors while the engine is running to ensure they are pulsing in a similar manner

Lubrication System

Check the manual to see which parts require greasing – clean old grease off first then add marine grease to:\

  • All control cable, joints and end fixings
  • The gear shift mechanism
  • Unpainted metal parts
  • Splined propeller shafts (do not grease tapered & keyed shafts)
  • Change the oil and filters at regular intervals – warm the engine up first, then turn it off and suck the oil out using a hand pump.
  • Smear clean oil around the new filter gasket, and fill it with oil before screwing it on. Hand tighten

Air System

  • Remove & check the air filter
  • Check the engine compartment ventilation
  • Check the colour of the engine exhaust

Cooling System

  • Check for water leaks
  • Check all hose clamps are tight and rust free
  • Check all hoses for chafing, kinks & cracks
  • Check the seacock
  • Clean the strainer
  • Learn how to replace your impeller
  • Learn how to replace the thermostat


  • Flush any white fur from the terminals with hot water.
  • Check the clamps are tight and smear battery terminals and clamps with petroleum jelly or other terminal protection grease
  • Check battery fluid levels. Add distilled water to just above the plates (always wear eye protection)
  • Check visible wires and connections are clean and tight. Check wires aren’t frayed broken or corroded
  • Add cable ties to keep cables tidy and free from chafing
  • Check anodes & replace if 2/3 gone
  • Check all belts and learn how to adjust the tension if necessary


  • Clean and grease your propeller regularly
  • If you have a stern gland know how to grease it and how to look after your stuffing box
  • Check the gear cable and connections

Engine Space

  • Keep the engine bay spotlessly clean so that any presence of a new fluid could indicate a possible problem:
  • Water – could be fresh or salt
  • Oil – check for leaks & drips
  • Belt dust – check belt tension & alignment

Trouble Shooting 

Engine will not turn over and a clicking noise is heard

  • Flat battery, poor connections, check wire between battery & engine?
  • Faulty solenoid?
  • Starter motor jammed?

Engine turns over but will not start or is hard to start

  • Blocked fuel filter?
  • Fuel turned off, is contaminated or has run out?
  • Air in the fuel system?
  • Engine in gear?
  • Injector pump fault?
  • Faulty injector?
  • Stop control activated
  • Air filter blocked?

Engine Overheats

  • Air filter blocked?
  • Cooling water low?
  • Raw water filter blocked?
  • Seacock shut?
  • Drive belt on water pump broken or loose?
  • Broken impeller?
  • Lack of oil in engine
  • Faulty thermostat?
  • Heat exchanger blocked?
  • Blocked exhaust?
  • Valve timings incorrect?
  • Valves leaking?
  • Faulty injectors?

Oil Pressure Low or High

  • Oil level too low?
  • Faulty oil pump?
  • Wrong grade of oil?
  • Oil cooler blocked?
  • Worn bearings?
  • Faulty pressure gauge?
  • Oil pressure relief valve faulty?

Black or Grey Smoke from Exhaust

  • Air filter blocked?
  • Engine compartment vent blocked?
  • Exhaust pipe blocked?
  • Faulty thermostat?
  • After cooler clogged?
  • Cold start aid fault?
  • Injection pump fault?
  • Injection pump timing out?
  • Inlet manifold leaking?
  • Faulty injectors?
  • Dirty hull?
  • Overloaded?
  • Fuel return line blocked?
  • Poor compression?

To check your injectors – they should all feel the same when they are working. A rhythmic pulsing has they operate in turn. If one injector feels different, then it may be faulty. Be careful as they are very hot!!

White or Blue Smoke from Exhaust

  • Blocked air filter?
  • Oil level too high?
  • Wrong grade of oil?
  • Crank case breathers blocked?
  • Glow plug fault?
  • Thermostat fault?
  • Poor compression?
  • Turbocharger oil seals worn

Engine Lacks Power

  • Blocked air filter or compartment vent?
  • Air or other blockage in fuel system?
  • Overheating?
  • Lack of oil?
  • Blocked exhaust?
  • Faulty injection pump or timing wrong?
  • Injector pipes leaking or broken?
  • Inlet manifold leaking?
  • Faulty injectors?
  • Damaged propeller?
  • Faulty thermostat?
  • Faulty turbocharger?
  • Poor compression?
  • Dirty hull?
  • Trim tabs stuck down (if applicable)

Engine Misfires

  • Air filter blocked?
  • Air or other blockage in fuel system?
  • Fuel filters blocked?
  • Overheating?
  • Fuel lift pump fault?
  • Leaking or blocked fuel pipes?
  • Glow plug fault?
  • Injection pump or timing out?
  • Injector pipes leaking?
  • Poor compression?

Banging or Knocking from Engine?

  • Faulty fuel lift pump?
  • Air leak on suction side?
  • Wrong fuel?
  • Low oil?
  • Overheating?
  • Shaft coupling loose?
  • Engine mounts loose?
  • Worn bearings, pistons, rings or cylinder bore?
  • Valve clearances incorrect?
  • Valve timings incorrect?
  • Valves sticking?
  • Glow plug fault?

Excessive Engine Vibrations

  • Air filter blocked
  • Engine and shaft out of alignment?
  • Engine mounts loose?
  • Shaft coupling loose?
  • Propeller shaft bent, unbalanced or broken?
  • Damaged propeller?
  • Control system fault?
  • Faulty injectors?

Engine Runs Unevenly, Surges or Hunts

  • Fuel tank running low?
  • Air filter blocked?
  • Air in fuel or other fuel blockage?
  • Fuel tank air vent blocked?
  • Glow plug fault?
  • Stop control faulty

Phew! So there you have it! I have certainly learnt a lot by doing this course. The text book itself comes with a lot more detail and lots of pictures and diagrams of how everything works. I will be keeping this on board with all the engine manuals so I can refer back to it in future. If you want to do the course too then you can either do it in a class or home study. More info is on the Coastguard Boating Education Website.

19 thoughts on “Diesel Engine Maintenance

  1. Bravo ! Our diesel course was “the school of hard knocks” with a 22 year-old boat, but it looks like we covered the same material. The new challenge will be the new boat with new motor… no one else to blame if things get fouled up ! Thanks for the refresher course !


  2. Fantastic notes! You’re going to be the best educated cruiser out there 🙂 If you don’t already have it, I love Nigel Calder’s book Boatowner’s Mechanical and Electrical Manual—covers a lot of diesel engine stuff (he also has a separate book on engines) as well as circuitry and much more. A must-have on every cruising yacht!


  3. Darling – I would love to sail with you- I am really great as ballast – and I normally check angles by looking at the liquid in my glass.


  4. Thanks, Viki, excellent details and writing (as usual).
    I do, however, have a rather different view on this which might upset one ore the other sailor (or, possibly, almost everyone): I simply cannot believe how much time folks spend “down there” maintaining or repairing their boat’s engine (or rather: engine system) when the main mean of getting from A to B is located on top of their boat. A motor I see as support only, it is after all a sailing boat we are talking about. I do see that it can be very useful maneuvering in marinas or helping out in calms or opposing winds. But sometimes I do get the impression that we sailors only get into those situations of needing a motor because in the back of our minds we know it is there… It is vital to look after the equipment one has on board, I won’t argue about that (whatever is on board needs to work). The question is whether it would make more sense to have a motor with less maintenance needs (and very likely less power) on board and spend the time saved on practicing maneuvers under sail…
    Ok, now you can all start your virtual bashing 😉
    Take care,


  5. Nice write up! One lttle note on how it works; diesel engines don’t mix the air and fuel together before the compression stroke. Diesel engines first compress the air which super heats it, then the fuel is injected. This is why diesels are so much more efficient then petro engines; they don’t need a stoichimetric mixture to run.


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