Archive for the ‘Mechanical “How-To”’ Category
Read on, to learn how to make that propulsion repower dollar go further!
Reconditioned Marine Propulsion Engine or New?
Begin your repower project by learning the relevant State and Federal requirements for marine repowers in your area.
Reconditioned engines work best when they can replace like-for-like engines. This reduces the expense for new accessories such as motor mounts and the electrical panel. Reconditioned engines are often good for 10,000 to 20,000 hours depending on how well they are maintained. Later model recons are quite fuel efficient when compared with older engines, especially two-stroke Detroit Diesels. They are simple to maintain and any qualified diesel mechanic can repair them. Well built four-stroke recon engines will perform like new. They are also roughly 2/3rds the price of new engines; however they typically carry only 90 day warranty.
New electronic engines on the other hand, are very fuel efficient, cost more money, and when they need work, they may require an engine dealer who has the computer software to do full diagnostics. New engines will last from 20,000 to 40,000 hours depending on maintenance, and the warranty period for most new marine engines is a full two years or 2000 hours, whichever comes first.
Saving time and dollars begins with an assessment of the running gear. If the boat’s transmission is still good and the propeller shaft is straight, the best and least expensive repower for your boat is as follows:
1-Select a replacement engine near the same power level and rpm as the engine to be replaced. This enables re-use of the same size propeller, keel cooler and exhaust piping. The savings here can easily be tens of thousands of dollars. Pay particular attention to the rear housing and flywheel size so they will mate to the existing transmission. Advertise your old engine before removing it. This gives prospective buyers time to hear it run, and they’ll be willing to pay more if it’s in good shape.
2- Before removing the old engine, get somebody to do an exhaust system back pressure test to learn if the silencer (muffler) is plugged. If it is plugged replace it.
3-Leave the transmission bolted in place.
4-Remove the old engine, clean the area under the engine, and paint it white.
5-Clean and pressure test the keel cooler.
6-Replace the front seal on the transmission and the rubber drive blocks (or flex coupling) between the transmission and engine. We also recommend replacing the transmission oil cooler because it’s difficult to be totally certain they are free of debris, even after thorough cleaning.
7-Bolt the replacement engine to the transmission, and make all of the connections.
8-Beside the cost to install the replacement engine, be sure to include these items:
a-$1000 to verify the final alignment on the shaft and engine,
b-$1000 for cleaning up the boat’s DC electrical system, and
c-$1000 for upgrading the old drive belts and hoses in the boat. (Including hoses that run to the hot water heater, if so equipped.)
9-No matter if the replacement engine is new or reconditioned, be sure to have the technician install a fuel system sight glass (MER PN 33448A) between the boat’s Racor fuel filters and the engine fuel system. During the sea trial they must verify that no air bubbles are entering the engine fuel system with the fuel. If they see air coming in with the fuel (called a suction leak), they must find the suction leak and repair it.
With good planning your repower will cost far less: Long term fuel savings will be icing on the cake. Last of all, let us know how it goes!
- Figure 1-The Multimeter
Every boater needs a multimeter!
That’s because today’s boats are stocked like a RadioShack, with a huge variety of electronics. All of it looks complicated, but with a good multimeter and careful study of the accompanying manual, as a refresher in basic electricity, it is possible to maintain most electronics. The multimeter (Figure 1) qualifies for a spot in any tool kit for tracing equipment failure back to its source. Depending on the brand and price, multimeters, which are also known as volt-meters, and Fluke meters, have a range of usefulness that we’ll categorize into three main groups: 1-Must Have, 2-Very Handy, and finally, 3-Useful. This discussion focuses on digital multimeters, however there are helpful links at the end of the article. These links will take you to Fluke, Simpson Electric Company (a source for more on analog meters), and other manufacturers of good equipment. Just reference Figure 2 for specifics as you dive into this important subject. We’ll begin with a word on multimeters in general.
Multimeter Functions:
First note that there are many brands and configurations of meters available. We will reference the Fluke 78 (Figure 2) shown below, which, by the way is one of the meters used by our techs every day. No matter which meter is used be sure to keep the operating manual nearby for quick reference.
Mode switch-This switch turns the meter off and on and also selects the kind of testing desired. Pressing the mode button in the center of the switch knob shifts operation to the alternate function for the mode selected.
Digital display-Provides not only numerical readings but also has icons that appear as different modes are selected. We’re all getting used to touch screens, but these are not touch screens. They can be damaged by sharp objects or even by pressing on the screen too hard.
Plugging in the test leads-For this meter, most tests are done with the leads plugged in on the right side of the meter as shown above. The exceptions are “Amps”, which use both the bottom right “common” jack and the bottom left “Amps” receptacle. Note: standard leads can test up to 10 amps, while amp-clamp leads are used above this level.
Figure 2-The Working Multimeter
1-Must Have:
A.C. and D.C. Volts-Simply stated, “Is it electrically hot?” This is the most important thing to know when working with electrical items. Use caution here: According to MER Service Manager Herb Knight, 120 Volts Alternating Current (A.C.) kills more people every year than all other voltage levels combined. Beyond self preservation, the multimeter will help determine if an electrical component or circuit has the voltage it is supposed to have.
The Fluke 78 has the A.C. Volts/Frequency together as shown above. Switching to this mode enables the testing of A.C. voltage, until the alternate function key is pressed. When pressed, the meter displays a read-out of the frequency of the A.C. power being tested. The units of measurement for frequency are in “Hertz” which is abbreviated as Hz. Alternating Current is found in generators, utility power and some engine sensing and control circuits. A measurement of alternating current, this test mode checks for the number of cycles per second (frequency). Household power in the United States is 60Hz, while many other areas use 50Hz power.
D.C. Volts/Frequency is for testing direct current (D.C.) voltage, or alternately D.C. frequency. D.C. frequency tests are done on specialized control systems and certain D.C. motors. DC voltage readings are taken on engine starting and charging systems, as well as some control circuits.
However, if no voltage is present it is time to find out why. That’s where resistance testing comes into play.
Resistance/Continuity Beeper-In laymen’s terms, “Does the juice have a clear path to travel?” One of the most common marine electrical failures results from corroded electrical connections, whether at splices, or terminal connections. Resistance testing measures electrical resistance in Ohms, and alternately the meter’s beeper will sound when there is continuity in a system. A zero reading (0.00) means the circuit is open. Readings of 0.1-.3 ohms can indicate either a short or complete circuit. Like the diode check function, the continuity circuit sends current through the leads and the horn will beep if there is a complete circuit.
2-Very Handy:
D.C. Amperes/A.C. Amps-Very low ampere readings (less than 10 amps) may be done with both direct and alternating current using the standard leads, however, read the operators manual to learn when to use “amp clamp” style leads with a clamp-on end on the red test lead. The unit of measurement for current flow is the Ampere (amps).
- Figure 3-Fluke makes many test meters, including this model with a built in amp-clamp.
Diode Check/Temperature-Diodes are tested in this mode. The meter applies a small voltage through the leads to check the direction of flow through a diode. A reading of 0.3-.5 Volts in only one direction mean the diode is good. Alternately, when fitted with thermocouple leads this meter will measure temperature.
RPM/Speed-is a tachometer function for measuring rotational speed.
Frequency-This function is bundled with voltage on the meter we’re showing above.
3-Useful:
Duty Cycle/Percent-is used with position sensors. Engine control systems use current with pulse width modulation, and this meter function measures the percent of time “on”.
Temperature/Diode Check-When fitted with thermocouple leads this meter will measure temperature. Alternately, diodes may be tested in this mode. In this mode, the meter applies a small voltage through the leads to check the direction of flow through a diode. A reading of 0.3-.5 Volts in only one direction mean the diode is good.
“RPM” testing-is done with special leads and uses both of the left hand receptacles.
Auto Mode-Most meters are in auto-mode by default, and this enables near instant range changes for measuring widely varying voltage. Consult your manual to learn how and when to use manual mode.
Finally, note the following list of important multimeter related links:
Fluke USA:
http://www.fluke.com/fluke/usen/home/default
ESI Test Inc.:
http://www.esitest.com/
Simpson Electric:
http://simpsonelectric.com/
MER Hydraulic Power Units (HPU) power skimmers for the Gulf oil clean-up.
MER supplies heavy-duty Hydraulic Power Units (HPU) to the US Navy, oil spill response contractors, and Alaska’s commercial fishermen. The range of HPUs is from 20 gallons per minute (GPM) to 350. The machines are similar to a generator set except they make useful hydraulic power instead of electricity at variable engine speeds.
MER also makes Hybrid units that produce hydraulic power and electrical power. HPU cooling options include radiator, heat-exchanger, or keel-cooling. Keel-cooling is the method of choice for machines like oil skimmers, that must operate in contaminated waters.
Standard Equipment: Hydraulic oil heat-exchanger, Variable speed throttle, Manual oil change pump, Gauge panel, 12V Starting/Charging system, and Anti-vibration mounts.
Optional Equipment: Air or hydraulic clutched pump drive, Electric clutched pump drive, Pumps can be driven from either end of the engine or side-mounted. Remote start and stop, Extension harnesses, Gear, vane or piston pumps, Pressure compensated pumps, Load sensing, Skid mounted hydraulic reservoir. There is a variety of hydraulic filter options and Quick disconnect hydraulic connections, Custom base frame geometry, base frame materials in steel, galvanized steel, stainless steel, and aluminum. Also Integral fuel tanks and or hydraulic oil reservoirs, Integral drip pan, Engine driven air compressors, AC Generator opposite the hydraulic, pump drive.
- Figure 1 The Final Welded Mount Foot Fits Perfectly
Call Gary, Norm, or Ben C. at 800-777-0714 To Order Yours: Weld-up mounting feet are available from MER to make engine, transmission, and generator mounting much faster and easier. The finished product, seen below, works with your existing mount holes on the engine block or transmission, to properly place the slotted plate, and provide a place for the adjustable mount to fit beneath.
Figure 2 The Vertical Plate Can Be Turned Over If Need For Your Aplication
To get to this point, suspend your engine, transmission, or generator from a hoist or block it safely in the position needed. Next lay out the MER pieces as shown, and be sure to leave .5″ of threads below the slotted plate, to allow for later adjustment of the mount itself. Tack weld them, and do a careful trial fit, making any needed adjustments before the final welding.
Figure 3 Be Sure to Leave 1/2" of Adjustment Below the Slotted Plate For Later Adjustment
Engine Installation angle affects the dipstick oil level reading.
When engines (and transmissions) are installed at an angle, the oil pan’s oil-level changes, front-to-back. If operated at extreme angles without re-marking the dipstick, the engine can fail, due to lubricating oil starvation.
This is because, without re-marking the oil level will appear way too high. If the excess oil is then drained down to the full mark, the engine will be running low on oil! High speed engines change all of the oil in the pan every 10-15 seconds. If you’re running with less oil than needed, the oil gets a severe workout and will not last the full oil-change interval. What’s more, running a low oil level may actually starve the engine for lube oil.
Each manufacturer knows how much an engine can be angled before the oil level gets too close to the rear oil seal. If the oil level gets above the oil seal, the seal will fails. Engine makers publish their maximum installation angle guidelines, and these specifications vary widely between engine models. It is to your advantage to verify the installation angle of your engine, and proper marking of the dipstick.
However, after the engine is installed,the next step is to re-mark the dipstick. To do this, always review the engine makers directions for re-marking the dipstick!
Then, based on the manufacturer’s recommendations, continue by warming up the engine to be sure all internal passages and the filter, are full of oil. Next, drain the oil from the engine, leaving the oil filter un-disturbed. Now, refill with the factory specified amount of oil, minus the amount in the oil lines and filter. MER Service Manager, Herb Knight stresses the importance of taking into account the volume of oil the filter and oil lines hold, especially if using a remote oil filter. Subtract this amount from the amount of oil poured back into the engine.
Make note of exactly where the new “Full” mark must be, and for composite dipsticks like the one shown here, file a shallow ring all the way around the stick, to make the new mark. For steel dipsticks however, lightly file the new “Full” level mark across both sides of the stick, above the old mark.
For all dipsticks, finding the new “Add” mark is obtained by measuring the distance between the original “Full” and “Add” marks.Finally, make the new “Add” mark the same distance below the new “Full” mark.
MER sells John Deere Oil and Filters, as well as a complete line of filters for all engines.
Use The MER Fuzz-Buster Magnet To Extend Transmission LIfe
MakingHappy Customers
Is it OK to brag just a little bit about MER’s famous service!? The short piece that follows explains how our customers feel about our service:
Dear Stevie ,
Thank you so much for your expeditious help with and handling of my KBW10 transmission needs. I was more than a little depressed when I had to come to Seattle yesterday to pick up the unit; not knowing what to do nor where to go for straight answers and a solution. Thanks to the internet for information/location regarding MER… and after stopping by and meeting you all … the cloud of uncertainty was lifted…and now the solution is at hand. I was impressed with the people at MER and I enjoyed meeting you in particular. Everyone was friendly and seemed genuinely interested in helping me with my problem…all qualities of a progressive and successful business. Thanks for being there for me and for your careful and efficient handling; I’ll look forward to seeing you again when I pick up the old core and the new transmission.
Best regards,
Maury Hafford
Making Your Aluminum Case Transmission Last Longer
The MER Fuzz-Buster Magnet, for aluminum case transmissions, sits on top of the regular filter. As the transmission runs, thousands of gallons of oil flow through the magnetic field that is projecting through the stream of oil.
For a quick visual check of the transmission condition before a trip, just lift the filter lid and shine a light on the magnet. If it’s clear of metal particles, you are ready to travel.
However, if there is over 1/2 thimble full of metal fuzz on the magnet, you better have it checked. To service your transmission and get started with a Fuzz-Buster, follow these instructions:
ZF-80 Transmission Filter Service
1-Using a 6MM allen wrench, turn the screw counter clockwise to remove the oil filter lid (1).
2-Lift the old filter (2), from its position.
3-Place the MER Fuzz-Buster Magnet (3) on top of the new filter, taking care to center it on the new filter.
4-Replace both oil seal o-rings (4 & 5), and re-assemble.
Changing The Oil
If there is a drain plug it will be at the bottom of the transmission, at the rear, just under the output shaft flange.
1-Remove the drain plug and drain the oil into a waste container.
2-It is a good habit to hold the drain plug in your hand until it is replaced in the drain hole and tightened.
3-Refill the transmission with Dextron 2 transmission oil-this is a red oil. Run the engine and check for leaks, and re-check the oil level again.
However, not all transmissions have a drain plug. If yours doesn’t, use a suction pump to remove the old oil. These pumps are available through MER Parts.
1-Remove the dipstick.
2-Insert the suction pump tube to the bottom of the transmission, through the dipstick hole.
3-Pump all of the old oil into a waste container.
4-Refill the transmission.
5-Run the engine and check for leaks.
Comparing Gas And Diesel Engine Combustion Chamber Locations
This drawing compares the location of combustion chambers between many, if not all gas and diesel engines. This important difference becomes critical after an engine submerges or gets water, fuel, or coolant above the piston.
When an engine is hydraulically locked like this, there is a night and day difference between the two engine designs, and how to go about clearing the cylinder.
With the gas engine on the left, notice that simply waiting a while will allow most of the fluid to drain down through the piston ring end gaps, and eventually you will be able to rotate the engine. Or, to hasten the process, you can pull the spark plugs and turn the engine over.
Notice however, that the top of the diesel piston is constructed so that the fluid cannot escape unless the injector is removed and the engine barred over to clear the fluid.
(Some of this material excerpted from “PRACTICAL BOAT MECHANICS”, by Ben L. Evridge, to be published this fall.)
Plug Critical Passages
When working around critical passages and scraping gaskets, be sure to plug the opening, as shown here. Next, scrape the gasket, taking care to work around the shop cloth. This practice will protect the engine from contamination.
Scraping The Gasket
Unplug The Passage When Finished
(Some of this material excerpted from “PRACTICAL BOAT MECHANICS”, by Ben L. Evridge, to be published this fall.)
Ratio Of Steering Cylinder Travel To Rudder Arm
Remember these important ratios that make or break your boat’s handling.
1-Ratio Of Steering Cylinder-To Rudder Arm Travel: When steering components are changed or a new boat is built, the steering helm can require too many turns to steer the rudder from lock-to-lock to be practical. This will also greatly reduce the steering effort. Or, if the system has insufficient turns, the effort required at the helm can be far too high to be practical.
To remedy these conditions, move the point of connection to the rudder arm out if the effort is too high. If on the other hand the system requires too many turns, move the point of connection inward toward the rudder shaft, even drilling an additional hole if needed.
Ratio Of Engine Speed-To Transmission Output Shaft Speed
- 2-Ratio Of Transmission Output Speed-To Engine Speed: When a diesel engine turns at 2,000 rpm and the propeller shaft turns at only 1,000 rpm, it is said that the drive ratio through the transmission of 2:1. Put another way, 2,000 rpm is going into the front of the transmission but only 1,000 rpm comes out the back. This is accomplished by using two gears inside the transmission running together. From the ratio we can see that the driving gear, the one from the engine, must have half the number of teeth than those on the gear that drives the propeller shaft. The gear reduction is what allows the engine, transmission, and propeller shaft to work together to move the boat efficiently through the water.
- 3-Ratio Of Governor Lever-To Throttle Control Movement: The response of engine speed acceleration can be changed by altering the ratio of the control-to the throttle lever movement, as shown.
4-Ratio Of Transmission Shift Valve-To Travel Of Shift Control Movement: The same is true for the shifting mechanism.
(Some of this material excerpted from “PRACTICAL BOAT MECHANICS”, by Ben L. Evridge, to be published this fall.)
Troubleshooting Low Power Complaints
There are many mechanical or electrical things that can go wrong with any boat engine. Troubleshooting is the process of reducing the number of variables to a very small number of realistic possibilities that can affect the engine in question. The following list will help you find the problem.
Air Filter Obstruction-A plugged air filter will reduce power, and on boats a slight exhaust leak will quickly plug the filter. Just remove the filter and do a visual inspection by shining a light from the inside out. If you can’t see light through the filter it’s time for replacement.
Exhaust System Obstruction-A collapsed silencer or plugged exhaust system will lower power as well. Have your marine technician perform a back pressure test on the system to see if this is the case.
The Fuel Supply-The fuel supply system easy to forget. First of all, check your fuel level and make sure there is plenty of fuel in the tank. If there is no fuel-level gauge or the existing gauge is questionable, then you must dip the fuel tanks. And, while you are at it, apply a dab of water finding paste that is available from your fuel dock, on the end of the stick to check for water in the fuel. If your fuel level is satisfactory then move on to the fuel filters.
Check the fuel filters for the presence of water and to be sure fuel is flowing through the filter. If you have recently changed the filters, then check for air in the engine’s fuel pump and injector lines. This air may have entered the system during the filter change.
Another area to consider when power is low is fuel line sizing. Some older boats might have, for example, a one-half inch fuel pipe coming into the engine room. This line may have been enough to feed the original engines when the boat was built. However, over the years after the boat was re-powered and new generator sets were installed in the engine room, you may notice times when one or more of the engines seem to be sluggish. You may also notice that the lights brown-out when the main engine is also running because there isn’t enough fuel to supply engines. If so, it is time to upgrade the fuel supply line to what the factory specifies for each engine, plus a little extra. First calculate the cross section of the inner diameter of all fuel lines and then add them together. After getting the area of cross section needed to feed them all, go up to the next higher sized pipe to feed all of the engines adequately.
When upgrading fuel hoses, be sure to buy U.S. Coast Guard hose. See the following link:
http://www.yodio.com/yo.aspx?CardId=A7Jct5AjaL6EjjDvzGZtXJ
Inspect your fuel return lines as well. Some engines will not run well with a plugged or restricted fuel return line. Since most vessels have a valve on the return line, it is also important to check to see that the return line valve is definitely open.
A less common problem, but one that does happen, is accidentally filling up with No.1 fuel oil when you really need No. 2. This will reduce engine power because there is simply less energy in a gallon of No. 1 fuel than in a gallon of No. 2.
Controls-Verify that the governor speed control is getting full travel when you have the speed control in the full fuel position in the wheelhouse, or on the flying bridge. The transmission control needs full travel as well, and if you have a trolling valve, verify that it is closed when accelerating the boat.
Air in the Fuel-If you begin to bleed the air from the fuel system and the air just keeps coming, then it is time to use the sight glass.
A sight glass lets you spot air in the fuel. The place to install a sight glass is between the low-pressure fuel transfer (i.e., lift pump) and the high-pressure pump or unit injectors depending upon the type of injection system on the engine. Be sure to check the pressure that your transfer pump produces and be sure that your sight glass is rated for this pressure. Most major engine makers can supply a suitable sight glass through their parts sales organization.
If you can see even one bubble of air coming in with your fuel, then there is at least five percent air in your fuel. Air in the fuel will seriously limit the power the engine delivers and can cause hard starting as well.
When you do find air in the fuel, the next thing to do is to examine all fuel lines, hoses, fittings, and clamps between your engine and its fuel supply-on the suction side of the system. When air leaks into the fuel are repaired, you’ll feel the difference.
Electronically Controlled Engines-Verify that no trouble codes have been stored. If you see a code for a problem, contact your dealer and get a technician to plug in his laptop to find the problem.
Line In The Wheel-When nothing else is showing up as a problem, try this: With the engine stopped, take a hold of the propeller shaft with your hand and feel how hard it is to turn the shaft. Usually you can turn a shaft as large as 2″ inches in diameter by hand. If it’s hard to turn, get a diver to see what is wrapped around the shaft.
Further In-Depth Testing-When black smoke (mechanical engines) and hard starting are involved it is time to ask your technician to check the compression and fuel injection timing as well.
Questions and Comments-Please let us know your thoughts on this article and suggest new topics you would like to see.
(Some of this material excerpted from “PRACTICAL BOAT MECHANICS”, by Ben L. Evridge, to be published this fall.)