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marine engines & marine equipment
Marine Engines - Frequently Asked Questions (FAQ)
How do I align my engine?
Inboard marine engines should be installed so that the engine mounts are securely attached using the correct fasteners, aligned with the propeller shaft to a tolerance of .05 mm (.002 in) per inch of shaft flange diameter, measured at the engine and propeller shaft flange face, with the propeller shaft aligned and centred with the propeller shaft strut cutlass bearing and stern tube. During adjustment any flexible (ie rubber) engine mounts should be extended using pry bars or wedges to bring the engine into the same position it will be when the boat is under power at normal cruising speed. To determine engine mount deflection position under power, measure the position of the engine close to each mount with the engine stopped, and then measure it again under power (you can do this tied to the dock) using a dial gauge or fixed pointer. Excessive deflection of the engine under power may mean the engine mounts are loose or the flexible engine mount material is worn out.
When aligning the engine, adjust the alignment with the 2 rear engine mounts and 1 forward mount (for V drive engines adjust 1 rear engine mount and 2 forward mounts), leaving the 4th mount loose until the alignment is correct. Take up the clearance on the 4th mount with the lower adjusting nut or shims. Then tighten all 4 mount top nuts. This will prevent the engine block/pan from being twisted (and possibly cracked) during final tightening of the mount nuts. If the alignment changes when the top nuts are tightened, the 4th mount clearance was adjusted either too much or not enough. Engine mount deflection and engine alignment should be checked once per year, as well as whenever the boat has been lifted from the water, and mounts replaced or tightened and alignment adjusted as required. Always use "shakeproof" lock washers on engine mount nuts.
What size propeller should I use?
The boat must be fitted with a properly balanced propeller of a pitch and diameter that will allow the engine to reach rated intermittent rpm (ie Universal M3-20B: 3,600 rpm) for a few minutes during full throttle / top speed testing in normal conditions with a normal load.
If the engine is a diesel, before testing the boat at full throttle / top speed in forward gear make sure the engine can reach rated intermittent rpm at full throttle in neutral (high idle). Measure the full throttle rpm with a good quality mechanic's hand tachometer, and then back off the throttle to half speed and calibrate the instrument panel to the same rpm as the hand tachometer. If the engine fails to reach the rated rpm, or exceeds it by more than 100 rpm then the governor needs to be adjusted or the engine repaired before using full throttle for propeller testing. [If someone tells you it will damage the engine to use full throttle in neutral to test the governor setting you'll know they aren't used to working on diesel engines.]
Should I install a water separator fuel filter assembly?
Many marine engine problems are caused by water condensation in fuel tanks, water / dirt transferred from marine fuel depot (ie marina) tanks, or rain water leaking past the deck fill cap O ring. Clean fuel is just as important to gasoline engines as it is to diesel engines, and a water separator filter/fuel filter should be used for both types of engine. Diesel fuel filters with plastic bowls mounted in the engine compartment are required to have a metal fire-guard on the bottom to protect the plastic bowl. Gasoline engine water separator filters should not be fitted with a glass or plastic sediment bowl, or a bowl drain petcock. Fuel filter elements should be changed at least annually, preferably in the autumn. We recommend the Racor 320R-RAC-02 filter assembly for gasoline engines, and the Racor 500MA-P-10 filter assembly for diesel engines. Primary water separator filters should not use a filter element finer than 10 microns (ie do not use 2 micron elements on the primary filter) because it can cause fuel pump damage. Most modern marine engines also have an engine mounted spin-on type secondary 2 micron filter. If they don't a small pressure-type filter can be fitted near or on the engine to act as a secondary filter. The "P" in the Racor 500MA-P-10 model number specifies Filter Bowl Water Probe Assembly #RK21069, which works in conjunction with Water Detection Warning Module #RK12870 (a dash mounted warning light and buzzer which must be purchased separately) to reduce the need to drain water from the filter bowl every day when the boat is being used. We suggest the 500MA also be fitted with Bowl Drain Valve Petcock #RK19492 to facilitate bowl draining when it is necessary, and a vacuum gauge to indicate when the filter is clogged and must be replaced. It is not necessary to replace fuel filters simply because water has built up in the bowl and needs to be drained off, and the vacuum filter will help reduce the cost of filters being changed needlessly.
What oil should I use in my gas or diesel marine engine, and gas or diesel generator?
Use the type of oil recommended by the engine manufacturer in their owner's manual.
However, any well-known brand, viscosity SAE 15 – 40 will work fine in nearly all engines. 15 – 40 oil is designed to be a “fleet oil”, which means it is meant to be used year round in both gasoline and diesel engines... which is why it is marked with both the API specification “C” for diesel engines (Compression ignition) and “S” for gasoline engines (Spark ignition). We recommend Castrol RX SAE 15 – 40, however Shell, Exxon, and Chevron (and many other manufacturers) also make a good 15-40 oil. Volvo Penta and Crusader specifically recommend SAE 30 oil instead of a multigrade. SAE 40 is often used instead of SAE 30 in the tropics when oil temperatures exceed 80 degrees C. The latest API diesel specification is “CJ”, and the latest API gasoline engine specification is “SM”... if the can isn't marked CJ (usually CJ-4), then it isn't the latest specification diesel oil, the oil was packaged in Europe, or the oil was packaged by a manufacturer who doesn't find it necessary to mark the oil with the API classification (ie Volvo synthetic diesel oil).
Unless the manufacturer recommends it, do not use synthetic oil for the first 500 hours in both new and rebuilt engines, in order to ensure the piston rings seat properly (referred to as “break-in”). Monitor the oil consumption carefully... the engine is considered fully broken-in when oil consumption remains stable at less than a litre per 100 hours of running. Avoid long periods of high loads and high rpm during break-in.
Change the oil filter when you change the engine oil. Always use brand-name oil filters such as Fram, Wix, Hastings, etc.
Never use ANY oil additives. Do not switch brands. Do not overfill.
Should I add supplements to my oil?
No. Modern engine oil already has lots of additives, including detergents, dispersants, corrosion inhibitors, antioxidants, viscosity-index improvers, extreme-pressure additives, and 28 other chemicals. Do not add any oil supplements (ie Slick 50, STP, Marvel Mystery Oil, kerosene, diesel fuel, automatic transmission fluid, rotten bananas, etc) to the oil. Oil supplements can damage the engine, and can also cause integral clutch-type transmissions such as the Paragon transmission used in the Atomic Four to slip under full load. If you feel the need to add an oil additive product to the oil to free up suspected stuck rings or valves, try using 5-30 oil and changing it several times after approximately 10 hours of running. You can also buy a can of Engine Flush at an auto parts store and add it to the oil to flush the engine just before changing the oil. Stuck valves are usually caused by cold running or a leaking head gasket or a bad exhaust design allowing water to backflow into the manifold and exhaust ports from the water injection elbow, so before assuming valve problems are oil related, make sure the thermostat is bringing the engine up to the correct temperature: 140° F for raw water cooled engines running in salt water, and 180° F for engines equipped with heat exchangers, and that the head gasket and exhaust riser are in good condition and properly installed.
Should I add supplements to my fuel?
No. Modern engine fuel already has lots of additives: N-hexyl and octyl nitrate in diesel fuel, and anti-knock agents, scavengers, phosphorous additives, antioxidants, metal deactivators, surface-active agents, deposit control additives, deicing agents, dyes, octane boosters plus 43 other additives in gasoline. Adding any type of oil to the fuel dumps unnecessary oil in the water with the exhaust in the same way a 2 stroke outboard does. The Champion spark plug company "Spark Plug Handbook" warns "Champion does not recommend the use of fuel additives which leave deposits on the core nose of the spark plug". Under the heading "Splash Deposits" the Champion handbook states "the use of fuel additives, carburetor, and choke cleaners or other aggressive solvents before installing new plugs is the most common cause of this condition [splash deposits]", and under the heading "Fuel Additives" it states "red to purple deposits on one side of the core nose are an indication of fuel additives. While many of these deposits are non-conductive and do not contribute to lack of performance, some fuel additives contain octane boosters that leave conductive deposits on the core nose". Diesel secondary (final) fuel filters are so fine that they have been known to plug up with some fuel additives and cause engine failure. Do not add anything to your fuel tank except when you're putting the boat in winter storage, at which time you may want to add a small amount of gas line antifreeze to gasoline and diesel fuel conditioner to diesel fuel.
I'm installing a new diesel in my fibreglass boat, and I need to epoxy wood pieces to the inside of the fibreglass hull to use for mounting the engine and other accessories. What kind of wood should I use?
The best wood is dry, seasoned white oak.
What is a rebuilt engine?
A rebuilt engine is an engine that has had most of the larger lumps of rust scraped off with a paint scraper, some of the dirt and salt washed off with a garden hose, the crack in the cylinder head patched with JB Weld, everything (including the spark plug leads and flame arrester air intake ) painted any old colour with left-over cans of house paint, the old oil topped up with a mixture of Marvel Mystery Oil and STP, fitted with lawn mower spark plugs and 4 foot spark plug wires from an old V8 Chevrolet, a cheap gate valve installed in the thermostat bypass hose, initially started with a spray can of starting fluid after sitting outside with a tarp over it for several years, and advertised as "...completely rebuilt Universal engine, fresh-water cooled, like new, 2 year warranty, see it running, call Midnight Marine Supply - pager 999-9999"...
No, actually a rebuilt engine is an engine that has been completely disassembled, professionally stripped in industrial acid and hot tanks to remove paint, oil, dirt, cooling system / water jacket deposits, and then measured, machined, and reassembled with new parts so that all clearances are within the manufacturer's tolerances, and all normal wear parts such as seals, bearings, gaskets, filters, hoses have been replaced. At a minimum, rebuilt engines should have the valves and valve seats ground using valve and seat grinding machines (not grinding paste), the cylinder bore ridge removed, the cylinder bore honed to a cross-hatch finish, the piston rings replaced, and the crankshaft bearings replaced. The engine cylinders should be rebored or sleeved and new pistons fitted if the cylinder bore is worn beyond manufacturer's tolerances.
Do I need a tachometer?
No, a tachometer is not essential, although it is a popular accessory. A tachometer should be used initially to verify the correct propeller has been fitted, but once that is done engine speed is limited by maximum boat speed, and is directly linked to the boat speed shown by the boat knot meter, so a tachometer is not essential. Tachometers are used in land vehicles to determine the correct engine rpm for gear shifting, however since most marine engines have only 1 forward gear, the only use for a tachometer is to check engine performance and/or hull and propeller condition. Engine speed may be higher than normal in case of transmission clutch slip, a sheared propeller shaft flange or propeller key, a damaged diesel engine governor, or a damaged propeller, however excessive engine speed will quickly be recognized by a marked increase in engine noise and vibration.
How do I pick the right gauge and gauge sender?
Most electrical gauges except voltmeters and ammeters work in tandem with a variable resistance gauge sender. In order for the gauge to read correctly, the sender has to be matched to the gauge. There is no industry standard gauge sender resistance, and each manufacturer uses their own specification and design, so gauges and gauge senders from different manufactures usually are not compatible. As well, each manufacturer makes different resistance gauge senders for boats with single station controls and for boats with dual station controls (1 sender connected to 2 gauges) which cannot be interchanged. The wrong sender can instantly destroy a new gauge, or fail to warn the operator of an engine problem. For those reasons it is recommended that oil pressure, water temperature, exhaust temperature, manifold vacuum, fuel pressure, water pressure, etc. gauge senders be replaced at the same time gauges are replaced.
Cheap gauges usually work OK for a while, but are usually are not properly designed to withstand the vibration and corrosion inherent in marine use and break just when they're needed. The flimsy mounting systems on cheap gauges usually cause more lost time than was saved in not buying a quality product too, as well as causing a lot of problems with loose gauges and wires. For those reasons, and more, we only sell Stewart Warner (SW) marine gauges and senders, because we find that their initial higher cost is more than compensated for by their faster installation, reliability and accuracy.
I'm responsible for the maintenance of 2 charter sailboats, one with a Universal Atomic Four, and one with a Universal M25-XPB diesel. The owner's manual for the Atomic Four engine says the oil should be changed every 50 hours, and the owner's manual for the M25-XPB engine says the oil should be changed every 100 hours. How should I keep track of the engine hours, and does it make any difference if the hours are spent idling or at full cruise speed? Neither engine comes with an hour meter on the control panel, so I guess I need to install one on each boat, eh?
Hour meters are a very inefficient way to schedule an engine preventive maintenance (PM) program, because measuring the hours of use does not take into account the load on the engine while it was running, and engine load usually directly corresponds with engine wear... and engine wear is what is used to trigger a much more precise predictive maintenance (PdM) program.
A measurement that does correspond to engine load... and therefore engine wear, is energy consumption, which can be tracked easily by keeping a record of fuel purchases (some people use a specific credit card for boat fuel only, so they can get a regular report of fuel consumption on their credit card invoice).
Before fuel consumption can be used to schedule maintenance for a specific engine/boat combination the average fuel consumption per hour at full cruise speed needs to be calculated, usually by filling the fuel tank to the top, running the engine for exactly 1 hour under full cruise speed, and then measuring the amount of fuel needed to refill the tank to the top again.
For example, most direct drive Atomic Four engines burn an average of 4 litres (1 US gallon) per hour at cruise speed, so oil changes should be carried out when the Atomic Four gas receipts total approximately 200 litres (50 US gallons).
I'm installing an automatic bilge pump on my boat, and I plan to wire it directly from the battery so I can shut off the battery main switch and still have power to the automatic bilge pump when I leave the boat... besides, it's easier to wire that way. Another friend told me that although lots of people wire new appliances directly from the battery, he thinks that is the wrong way to connect anything. What is the correct way to wire an accessory that will be left on when the boat is not occupied, or any accessory for that matter?
Canadian Coast Guard regulations stipulate that before refueling, or in the event of an electrical fire, all electrical power should be shut off. Complying with that requirement can be very difficult to do quickly if some of the circuits bypass the battery main switch, ie are wired directly to the battery terminals... especially if the circuits are fitted with individual in-line switches and/or circuit breakers (which will normally be located in hard-to-find, out-of-the-way places).
To allow for quick and complete switching, as well as to ensure all circuits are protected with fuses or breakers, each circuit should originate from a fuse/breaker on the main 12 volt DC panel or an auxiliary 12 volt DC panel, all panels being fed from the battery main switch, so power on any circuit can be completely shut down quickly simply by turning the battery main switch to "OFF", or by turning off the specific switch/breaker for the circuit. Then... leaving the boat with only the automatic bilge pump activated is done by setting the battery main switch to the house battery, and then turning off all switches/breakers except the one that handles the automatic bilge pump.
Like most sailboats, my boat has a 4 position battery main switch mounted near the breaker panel. It has positions labeled "OFF", "1", "ALL", and "2". I asked one of the fellows who hangs around my marina what position the switch should be in when I start the engine, and he told me I should start the engine with the switch in the "1" position... but somebody else told me I should start it in "2" position... and another guy told me it depends on how the boat is wired. What switch positions should I use, and when?
First
check the boat wiring. It should be wired with absolutely no extra
leads directly off the battery terminals, including bilge pumps and
radios. All accessories and panels should be wired from the common
terminal of the battery main switch or from the main breaker panel
(or an auxiliary breaker panel), and each circuit should be protected
with a fuse or breaker. In a basic system usually found on boats
under 40 ft, only 1 positive "+" (red) battery cable should
lead from each battery bank to battery main switch positions #1 or #2
(a bank can have one or more batteries).
1. Switch position "1"
should be wired from the house battery bank - all the house batteries
which power the boat electrical system (ie interior lights, bilge
pumps, alarms) when the engine is not running... at least 2 big deep
cycle ones, although the more and the bigger, the better!
2.
Switch position "2" should be wired from the engine
starting battery bank... usually there is only one battery in the
starting bank, sized big enough to crank the engine rapidly in cold
weather for at least 3 minutes in 30 second bursts (with a cool-down
period in between each burst), in case the engine won't start.
Assuming the switch is in the "OFF" position when you board the boat, when you want to start the engine you should turn the main switch to the "2" position before turning the start key, and then switch to “ALL” when the engine is running. As soon as you've shut the engine off either turn the main switch to "OFF" if you're leaving the boat, or to "1" if you're staying on the boat or you're leaving the boat but you want to leave it with some accessories powered (ie bilge pump, alarms, etc). When you want to start the engine again either start it in “1”, or turn the switch back to "2" before turning the start key. Because the switch is always in the "ALL” position when the engine is running, both the house batteries and the starting battery are being charged whenever the engine is running.
My friend says when you run the #1 house batteries down so they're dead and then switch to "ALL" before starting the engine, the dead house batteries will put so much drain on the #2 emergency starting battery that all the batteries will then be only partially charged and the engine may not start without charging the batteries or boosting them from another charged battery. Is he right?
Yes, if the #1 house batteries are nearly dead and the battery main switch is turned to "ALL" before starting the engine the charged engine start battery will try to charge the discharged house battery and both batteries will be quickly left in a discharged condition so that the engine starter solenoid/motor will not activate until the battery switch is turned to #2 postion and the start battery is charged by a battery charger, or boosted from another charged battery. Running any battery to a dead condition drastically shortens battery life... if the house batteries frequently are used until they are dead either reduce the electrical load or install more house batteries.
What is a "lowball" quote?
A "lowball" quote is an attempt to be the successful bidder for a job by quoting so low that the bid is selected on the basis of lowest price... but as the repairs are completed the customer is informed one or more times that the original quote will have to be raised to compensate for the extra time and parts required to complete work that was not covered by the original quotation.
Sometimes there are unexpected problems discovered while work is in progress which are not covered by a legitimate quote (carpenters call them "Oh, ohs!")... they usually involve a crack in a casting or a component damaged by a previous repair attempt which was missed during the initial inspection and measurement phase (ie a pinhole leak in a block casting, a bent rod, a cracked piston, a stripped head stud thread, a galled marine gear shaft, a chipped gear, a cracked cylinder head, a defective thermostat, etc).
The mechanic told me I need a new battery because the old is "sulphated up". What does that mean, and how do I prevent it happening again?
Sulphation occurs normally whenever a battery discharges... it only becomes a problem when it prevents the battery from being recharged. When a battery is discharging the lead dioxide of the positive plates combines with the sulphuric acid liquid (electrolyte) in the battery to form lead sulphate, and the sponge lead of the negative plates combines with sulphuric acid liquid to also create lead sulphate. Charging the battery reverses the process, however if the battery is left discharged too long the process becomes irreversible even when the battery is charged, and that is what is referred to as sulfation. Sometimes charging a sulphated battery at very low amperage ("trickle charging") over several days can partially reverse the sulphation and allow the battery to be used again. The best way to prevent sulphation is to keep your batteries fully charged, as well as keeping your batteries well maintained by removing and cleaning the battery posts and cable terminals annually, keeping the top of the batteries clean, and topping the cells up to the level mark regularly with distilled water. If you have a late-model battery charger or inverter/charger with an “equalize” mode you can use that to remove sulphation.
A friend told me that the automotive antifreeze I use in the heat exchanger on my Universal diesel is very poisonous to pets, and that just licking it off a paw can kill a dog or cat. I understand there is a new kind of antifreeze that isn't so poisonous... is that true?
Standard antifreeze contains ethylene glycol, which is very toxic. Death follows convulsions and vomiting as the animal's kidneys are destroyed. "Lotto" (also known as "Pet Safe") antifreeze contains propylene glycol instead of ethylene glycol, and although it's not safe to drink, it apparently is much less poisonous than the ethylene variety. The bad news is that the 2 types can't be mixed... the cooling system must be drained (don't throw the old coolant in the water - it kills fish too!) and completely refilled with the new stuff. Both types of antifreeze should be mixed with equal parts clean fresh water (1:1 ratio) to give maximum anti-freezing and anti-boiling protection. Antifreeze should be changed every 3 years to prevent corrosion of the engine and heat exchanger, so the best time to switch to "LoTox" is at the regular change.
A friend told me that small Kubota diesels have a very good reputation for long life and reliability, and suggested that I replace the Atomic Four engine in my boat with a new Beta marine engine because Betas are marinized Kubotas. Is that true?
Yes, Kubota Corporation of Japan has a very good reputation for building reliable, clean-running small industrial diesel engines... and yes, Beta marine engines are marinized Kubota engines. Most small marine engines are marinized versions of 3 well-known industrial engine brands... Kubota engines are the basis of Beta marine engines (England), Westward marine engines (Canada), Nanni marine engines (France), Phaser marine engines (USA - Florida), and the oldest and best known: Universal marine engines (USA - Massachusetts - subsidiary of Westerbeke Corporation). [All Universal diesel engines are Kubotas.] As well, Kubota industrial engine dealers in many countries can supply a custom-built marinized Kubota diesel on request.
Mitsubishi industrial engines are used to build Sole marine engines (Spain), some models of Vetus marine engines (Holland), some models of Westerbeke marine engines (USA - Massachusetts), and several other brands.
Yanmar Corporation uses their own industrial engines to manufacture the Yanmar line of marine engines.
How tight should engine alternator belts be adjusted?
All belts used on marine and automotive alternator and water pump belts should be adjusted "just" tight enough so they don't slip under full load and top speed. You can diagnose a slipping belt by touch... belts that are slipping get very hot. Any tighter than necessary to stop slipping just puts an unnecessary load on the bearings and the side of the pulley, and can stretch the belt so it keeps coming loose. In most cases the correct tension is when the belt can be turned sideways but not backward with the fingers by a person of normal strength. Belts should be lubricated with belt dressing.
The warranty for my new Universal engine states that the propeller fitted must allow the engine to reach rated rpm at top speed and full throttle. Different propeller shops and manufacturers have given me conflicting specifications, and some have said that if the prop is sized to allow the engine to reach rated rpm it may not be as powerful at cruise. How do I pick the right prop?
Westerbeke and Yanmar, as well as other marine engine manufacturers, state in their warranty terms that propellers fitted to their engines must be sized to allow the engine to reach rated intermittent rpm at full throttle and top boat speed (direct drive Atomic Four engines used in displacement hull sailboats should be sized so the engine can reach 1,800 - 2,200 rpm). The problem is that as conditions change a prop sized for optimum conditions (flat water / no wind / light load / clean hull) will be too big under maximum conditions (rough seas / consistent strong headwinds / heavily loaded / fouled hull), and theoretically could cause engine damage, or at least could void the warranty.
My experience is that most computer propeller size calculators generate a propeller size for a waxed hull, no passengers, empty tanks, no cargo, no waves, no wind, no towed dinghy, and a brand new, perfectly tuned engine... in other words - a prop that is too big. However, sizing a prop for maximum conditions usually means it will be too small 99% of the time on most boats used for coastal cruising and will not give optimum performance during normal use. Therefore, it is important to explain to the propeller shop or manufacturer the average weather conditions and load for your specific boat, and fit a propeller intended for that kind of use.
Since maximum conditions are essentially enough force from a combination of waves, wind (ie head wind), load / hull condition to stop the boat, by tying the boat to the dock with a spring line and then running the engine in forward gear at full throttle (called a bollard test) you can simulate maximum load. In most cases the prop is sized right for coastal cruising if the engine rpm settles around maximum torque rpm (the torque curve on direct drive Atomic Four engines is flat, and so this method does not apply to those engines – depending on the prop fitted, direct drive Atomic Four engines usually run at about 1,400 - 1,600 rpm during a bollard test.) Engines in boats going offshore probably should pull a little higher than maximum torque rpm.
My marine supply dealer suggested I start using extended-life [red] antifreeze in my Universal diesel because it lasts longer. He says I can add it to the coolant in my engine right now without flushing the old coolant first. Is he right?
No. When replacing the coolant in your fresh-water-cooled Universal engine first drain (NOT into the bilge... collect it in a pail and dispose of it properly) and flush the system with clean water several times, then install new coolant consisting of a 50:50 mixture of clean fresh water [distilled is the best] and regular [green] anti-freeze. Do not use extended-life [red] antifreeze, it is not designed for cast iron marine engines with copper cooling components). Do not mix standard green antifreeze with extended-life red antifreeze, and do not mix different brands of antifreeze.
My engine suddenly overheated and it has lost engine coolant from the heat exchanger. What do I check to fix it?
The loss of engine coolant is probably caused by a leak, although if your catch tank was empty before then the engine may just have overheated without losing coolant. Fill the system with water (you don't need antifreeze until the engine is repaired) and pressure test with an automotive radiator tester (ie it pressurizes the system to force air/water out the leak). The usual cause of loss of coolant is a failed engine coolant pump (the engine coolant pump on diesel engines is driven by the alternator belt, and the pump has a hole in the bottom near the base which is designed to drip water when the seal fails so it can be checked quickly to see if it is leaking) or a leaking hose connection. Coolant loss can also be caused by an internal heat exchanger leak which is allowing the heat exchanger to leak engine coolant into the sea water. If the leak is internal you won't find an external leak on the outside of the heat exchanger.. you'll have to remove the heat exchanger and have it rebuilt at an automotive radiator shop or replace it with a new one.
Internal heat exchanger leaks are usually caused by a failure to replace the zinc in the heat exchanger regularly - before it is more than 75% eaten away by electrolysis.
Rapid zinc erosion due to electrolysis can be caused by a poor engine / heat exchanger ground connection, or by acidic engine coolant. Acidic engine coolant is usually caused by a failure to flush the cooling system and replace the engine coolant with the correct antifreeze / water mixture every 2 or 3 years, which allows the engine coolant to gradually become acidic.
You can test the heat exchanger for a bad ground connection with a digital voltmeter. Start the engine. Connect the negative lead of the voltmeter to the negative battery post or engine block negative ground stud and connect the positive lead of the voltmeter to the heat exchanger body... a reading of more than 0.1 volt means the ground connection is poor and should be repaired.
engine coolant is acidic and can cause pinholes in the heat exchanger.
You can test the heat exchanger for a bad ground connection or acidic engine coolant with a digital voltmeter. Start the engine and remove the heat exchanger pressure cap. Connect the negative lead of the voltmeter to the negative battery post or engine block negative ground stud and dip the positive lead terminal into the heat exchanger... a reading of more than 0.1 volt means the engine coolant is acidic and can cause pinholes in the heat exchanger.
If the heat exchanger has corroded internally you should check
The main cause of overheating is a blocked sea water intake (ie plastic bag, jelly fish, sea weed, etc), a failed sea water pump (ie usually the impellor fails), a stuck engine coolant system thermostat, or a plugged sea water exhaust injection elbow (the exhaust injection elbow gets blocked from salt deposits building up at the point where they are injected into the exhaust (it is common to misjudge the amount of water coming out the exhaust because the exhaust splashes the water nearby and makes it looks like there is enough water flowing, when in fact there is little or none). Check those pieces one-by-one and make sure they are OK. You can remove the thermostat and run the engine without it if you want to see if that makes a difference. You can also heat the thermostat in a pot of water and watch to see if it opens fully before the water boils (no matter what temperature it is rated at it should open fully by 212 F).
My friend says that alternators have fans behind the pulley which draw air through the alternator from the back, and that the wrong fan can cause an alternator to burn out. Is that true, because if it is why don't shops selling alternators ask what kind of fan my engine needs?
Your friend is right, alternators have a cooling fan which draws air into the alternator from the back and ejects it out the front around the belt pulley. Because an alternator will charge when it is rotated in either direction (clockwise or anticlockwise... facing the alternator pulley) and there is no standard rotation direction, many aftermarket alternators are fitted with bi-directional fans which can be used on any engine without changing the fan. Bi-directional fans are not as efficient as uni-directional fans designed to turn in one direction only, and in a hot sailboat engine compartment an alternator fitted with a bi-directional fan may run hot enough to burn out much sooner than expected, so most quality marine engine alternators are fitted with uni-directional alternator fans in order to keep the alternator as cool as possible.
My friend told me I should buy a "SpeedSeal" water pump cover for my diesel engine so I can change my water pump impellor quickly whenever it breaks. He says the knurled screws that hold the Speed Seal impellor cover on are designed to be loosened and tightened with the fingers and so the cover can be removed and replaced faster than by using a screwdriver to loosen and tighten the regular screws that hold the original water pump impellor cover on.
What, you don't own a screwdriver?! If the cooling system has a properly fitted sea water strainer and the sea water pump impellor is changed every 2 years like it should be then there will be no need for emergency impellor repairs... and therefore no need to deal with the real problem with a broken impellor, which is not installing a new one quickly without a screwdriver, but fishing out all the bits of broken impellor blade which have been pushed up into the pump outlet fittings, hoses, heat exchanger (or in the case of raw-water-cooled engines engine water jackets, thermostat, block and manifold fittings), anti-siphon valve, and exhaust water injected elbow... causing endless overheating problems by intermittently partially blocking the flow of water even after the new impellor is installed until all the bits eventually work their way through the system or are all retrieved by methodically cleaning each component. The SpeedSeal encourages extended periods between impellor changes on the grounds that a broken impellor can be changed quickly, which is a BAD idea.
I want to attach a 3 stage "smart" voltage regulator to the Prestolite alternator on my Universal diesel engine. The instructions for the voltage regulator say it will only fit on a "P type" alternator. What kind of alternator is fitted to Universal diesels?
The alternators on Universal diesels are "N type".
What is the thread on the new style engine mount studs fitted to all new Universal and Westerbeke diesel propulsion engines?
The engine mount studs on new Universal and Westerbeke diesels are 16 mm diameter with a pitch of 2.0 mm.
Lately when I try to start my old Universal diesel the solenoid clicks but the starter does not turn the engine until I've tried it 3 or 4 times. I charged the battery and made sure the alternator belt is tight and the alternator is charging. Should I replace the solenoid, or the starter and solenoid?
This is a common problem on older Universal diesels, because they take a lot of current to power the starter with the glow plugs also on, and many of them were fitted with rather small, and pretty long, battery cables. It is usually not the starter or the starter solenoid actually causing the problem, but because it's the starter that's not turning it's the first thing most people want to change (even though they're very expensive). The problem is often a voltage drop in the starter circuit - usually corroded battery cables up under the plastic (even though the terminals look nice and shiny), or a worn out battery main switch, or a bad ground at the engine, although sometimes it's just old batteries getting weak.
Make sure
your batteries are in good condition and fully charged. Turn the
battery main switch to the position you use for starting (usually the
starter battery is designated #2). Have someone hold the glow plug
button on to put a load on the battery and use a digital voltmeter to
check the voltage drop between each section of the battery cable
circuit as follows:
1: from the starter battery + terminal to the
battery main switch terminal for the starter battery
2: from the
battery main switch terminal for the starter battery to the battery
main switch terminal "C"
3: from the battery main switch
terminal "C" to the starter solenoid + terminal
4: from
the starter battery - terminal to the starter casting
Any voltage reading over half a volt means there is a resistance in the circuit that must be fixed. If there is no voltage drop remove the starter / solenoid and take it to an automotive electric shop for a rebuild. That is the most cost-effective way to get it repaired. Usually the shop will simply replace the solenoid as part of the rebuild.
My boat has an older 2 cylinder Universal diesel engine, and it seems to vibrate a lot. My friend told me I should install a flex coupling in the propeller shaft... he says it's easy to do, all I have to do is unbolt the coupling between the prop shaft and the transmission and move the prop shaft back enough to fit the flex coupling in between. Is fitting a flex coupling that easy?
The flex coupling we sell for the ZF 5 gearbox (aka Hurth HBW50) used on most small Universal diesels is 1.35" long. The correct spacing between the propeller hub and the cutlass bearing strut is the diameter of the prop shaft to twice the diameter of the prop shaft... ie you probably have a 1" shaft, so the correct spacing would be from 1" - 2". More than 2" clearance and the prop can cause the shaft to flex and let the prop wobble under full load. Installing the flex coupling with no other changes would move the prop back 1.35", which is OK if the clearance now is about 1". If the prop already has more than 1" clearance then installing a flex coupling would require removing the shaft, pressing off the shaft coupling, cutting the right amount off the end of the shaft, machining a keyway in the shaft, pressing the coupling back on, and then reinstalling the shaft.
Removing the shaft so it can be cut to fit the new flex coupling can be difficult if the shaft coupling flange is the solid type... if it is seized on (like most of them are) either the engine has to be removed (so the shaft can be pulled out after the prop is removed) or it has to be cut off with a hacksaw. The odd one can be removed by placing increasingly thick spacers between the shaft coupling flange and the transmission coupling flange and tightening the bolts to press the shaft out of the coupling... often this method cracks or bends the shaft coupling when it is seized on the shaft and it has to be replaced anyway. Even if the coupling comes off without cutting it... it can be very difficult to press on a fixed coupling flange with the shaft in place - the coupling flange has to be heated in boiling water to get it to expand enough so it can be hammered on, which isn't easy with the engine still in place unless there is lots of clearance to move the shaft forward enough to get space to work. In most cases a split coupling has to be used instead of a solid coupling. A split coupling is much easier to remove several years later when it is necessary to remove it to replace the shaft seal or stern tube too.
Most people install a grounding strip on the flex coupling to retain an electrical connection between the prop shaft and engine, since most boats use the engine as the boat grounding point.
Many people install a PSS dripless seal when they have the shaft off for modification.
When the shaft is out for modification is also a good time to install a new cutlass bearing.
A 2 blade prop running behind a large shaft strut or keel, a prop with too large a diameter (ie a prop without sufficient tip clearance between the blade tips and the bottom of the hull - 15% of prop diameter for a flat hull section above the prop), excessive prop hub to cutlass bearing clearance (ie as described above - more than 2 shaft diameters), zincs mounted in the middle of the prop shaft instead of close to the shaft strut, a bent propeller shaft, a bent shaft or transmission coupling, worn transmission thrust bearings, a worn cutlass bearing, an engine that has moved out of alignment as the hull gradually changed shape in warm weather, delaminated engine mount stringers (ie separating from the hull), worn engine mounts, loose prop strut/hull joint bolts, and a prop that is too large for the engine (ie make sure the engine reaches rated rpm at full throttle/top speed) can all cause excessive vibration, besides the vibration inherent in a 2 cylinder diesel (Universal no longer sells a 2 cylinder engine... even the smallest model is a 3, and it's much smoother than the older 2 cylinder models).
My friend told me dielectric grease is used in electrical system connection plugs and spark plug wire connections to improve electrical conductivity. Someone else told me dielectric means it doesn't conduct electricity. What is dielectric grease for?
Dielectric grease doesn't conduct electricity at all. That allows it to be used in multiple-pin electrical connection plugs to seal the pins against corrosion from moisture (ie salt water & moisture laden sea air) while still allowing the plug to be disconnected easily, and without causing any "cross-connections" between other pins in the plug. It is also used in spark plug and distributor terminal caps to seal the spark plug wire terminals against moisture while not creating a path or "track" for the high-voltage carried by the spark plug wires to leak away to the engine block or other wires, which would cause the spark plugs to misfire.
What is "break-in", and when is it over?
Break-in is the initial period of running time for a new or rebuilt engine when the rings and bearings are "wearing in" so they make a good fit, and in the case of the rings - so they seal properly against the cylinder walls. In order to allow a "tight" engine to break-in properly (ie without any metal-to-metal contact at tight spots which could cause permanent damage) it is usually not fully loaded for long periods and kept at medium temperature. Until the rings are sealing properly against the cylinder walls the engine will tend to burn a bit more oil than it will when fully broken in... therefore break-in is over when the rings are sealing properly against the cylinder walls and oil consumption has dropped to its lowest point and is remaining stable. A normal break-in period for a new or rebuilt Universal or Westerbeke engine is usually around 100 hours. Do not use synthetic oil or oil additives during the break-in period.
Some marine engine shops advertise that they have a "Master Mechanic" on staff. What does that mean?
There is no such registered trade as "Master Mechanic" in Canada, and I have never heard of there being one in the US either, although it is possible it is used in some states. The term "Master Mechanic" was sometimes used before World War II in mines in northern Canada to designate a heavy duty mechanic who also was trained as an electrician. It is sometimes used these days by sales staff to imply that an older mechanic is very experienced... often because he / she actually has no formal training or certification and doesn't want to be called a journeyman mechanic, since journeyman implies formal training and certification. The next time someone tells you they're a "master mechanic", ask to see the certification papers and license which proves they're one!
What is the difference between low maintenance batteries and regular ones?
This link answers that question and many others: www.uuhome.de/william.darden/carfaq14.htm#jump
The surveyor I hired to survey my boat told me all the hoses connected to through-hull fittings must be "double-clamped". I assume she means I have to install 2 hose clamps at each fitting instead of just one... is that what it means?
Yes, the surveyor wants 2 clamps side-by-side on all the fittings. This is an old "rule" that often cannot actually be carried out, depending on the type of hose fitting and clamps used.
In the old days hoses were connected to short lengths of smooth pipe that were made by cutting a short length of pipe with a hacksaw or pipe cutter and cutting threads in one end. As well, hose clamps were often narrow assemblies made from wire (usually not stainless steel) formed around a bolt and nut, not the wide "gear clamps" used now. Because the pipe was smooth and the hose clamp was weak the connection often leaked, it was often possible to pull the hose off the pipe simply by jerking on it, and if the clamp was not stainless steel it often corroded and dropped off quickly when the clamp rusted through. For all 3 reasons many manufacturers and government agencies specified "double clamping" the connection.
These days cast brass or bronze "hose barb" fittings with specially designed ridges to grip the hose are used instead of pieces of pipe, and most do not have (or need) a barb long enough to accept 2 gear clamps. When 2 gear clamps are installed on these fittings, the inner clamp will not only not be clamping the hose to the barb... it's actually only decoration to make the surveyor happy, but it if it's tightened to much it may actually act to pull the hose off the barb, or cut the hose and allow it leak - exactly the opposite of the rationale for "double clamping" in the first place. This is typical of the recreational marine industry... they've sacrificed any pretense of quality of reliability for lowest price, which is apparently what they think their customers demand.
What is the correct fresh-water (engine coolant) pump for my Universal 5432 / M-40 diesel?
The Universal 5432 engine is based on a Kubota block, stamped V-1501 beside the fuel injection pump.
The Universal "Quick Moving Parts" sheet states the correct water pump for the 5432 is part number 300647. However, the Universal 5432 parts manual states the only correct pump is part number 298845.
The Universal M-40 engine is an upgraded and renamed 5432 based on a Kubota block, stamped V-1502 beside the fuel injection pump.
The Universal "Quick Moving Parts" sheet states the correct water pump for the M-40 is part number 300041. However, the Universal M-40 parts manual states the correct pump is either part number 300041 or part number 298845 (there must have been some early M-40s with the 5432 pump).
The Canadian price list gives the retail price for the 300647 pump as $CAD551.26, the retail price for the 298845 pump as $CAD441.37, and the retail price for the 300041 pump as $CAD495.09.