Tech Net E

Query: My bow thruster motor is getting overloaded. Could the cause be from growth? It was cleaned recently.
That's a good possibility. Clean the props.
It could also be debris, such as a plastic bag caught in the prop.
Check for saltwater intrusion in the motor.
Check the wiring connections.

Alternator shops will work on bow thrusters.

Query: Can brushes be modified to fit?
Yes. Be sure they're rated for high current.
Polish commutator to make brushes last longer.
Remove all debris after sanding to prevent shorting.

If you're facing symptoms of varying speeds under load, check for a fault where the wire goes through the brush. (C_Language)


Issue: Need to repair wind instrument display backlight.
You may introduce moisture by opening the instrument.
It should be a straight forward job. Do be careful not to strip the screws. (Moira)


I Fished it Out. Now What Can I Do?
Sometimes electronic gadgets go swimming.
1. First, remove the battery.
2. Use distilled water to remove any salt.
3. Rubbing alcohol will evaporate water intrusion on electronics.
It can also help remove salts.
4. Allow plenty of time to air dry.

(also moisture intrusion)

A hearing Aid App can be bluetooth-speaker connected to equipment to help amplify sounds such as GPS alarms or from an ssb net. (Moira)

Use contact cleaner to clean internal wire connectors.
I used this on my ribbon connectors on the tachometer. It solved the problem with failure of back lighting. (Final Lee)

Strike-Hold is another good product for cleaning electrical connections. (Beluga)

Trinity Marine Electric (no website)
4969 SE Dixie Hiway Stuart, FL 34997
phone 772.631.5723 (Kabria)

(also Tech Net Library)


The U.S. Coast Guard monitors the single sideband radio at the following time and frequencies:
2300-1100 zulu on 4152
24 hours on 6215 and 8291
0700 - 2300 zulu on 12290
Live Time Converter for zulu.

SSB frequency 4100 is monitored by the Spanish Wells fishing fleet.  It's something to remember if you're in need of contact while in the Bahamas.

USCG information about VHF frequencies and their purpose.
USCG information about HF Simplex frequencies.
USCG Intership Safety and Operational Communications.
Float Plan

Farkwar  Online App for Posting Your Offshore Position
Use Airmail, sat phone, ham radio, or the internet to update your position.  Input your ship's offshore position from nearly any place at any time.  Set it up to notify family and friends of your whereabouts instantly.


Query: When you see a light flash on the Epirb, what is it saying?
It's an internal test.

Test your Epirb at least once a year.

Epirb or Apirb. The price of batteries for them has finally dropped down.

McMurdo is a personal locator beacon. It's a good brand.

Spot Satellite Messenger is not just another hand held GPS. It links to Google Maps, and has an optional tracking feature, an emergency 911 beacon, and more. Read the Gizmo Report. West Marine carries it. (Chiquii)

Boat U.S. has partnered with SPOT as SPOT Assist. Boat U.S. members can add the automatic connection to their Spot Satellite Messenger with TowBoat U.S. or Vessel Assist for just a nominal fee. Details.


Issue: Yanmar diesel turbo charged engine is producing a lot of black smoke.
Clean the air intake.
Pitch on your newly installed props may be off if running at high RPM.
Run for a short period without the air filter.
Use a strobe or stethoscope (for sound) as diagnostic tools.
Check exhaust elbow for blockage.
Old or bad fuel may be a contributory factor. (Hold Fast)
Exhaust hose between muffler and engine may be choked with build up. (Scotch Mist)

Issue: The batteries and water level are fine, but he engine won't start. The starter is hot to the touch.
Take voltage measurements when attempting to start. There maybe a bad connection or a corroded wire.
Check connections for heat. Are they warmer than they should be?
The exhaust manifold maybe hydro locked if rough seas entered the exhaust hose.
Pull the injectors, spin the engine, then replace the injectors.
Flush the injector hole with fresh water to remove any salt.

Query: What should I use on engine mount bolts?
The objective is to prevent loosening and to prevent a seized bolt down the road.
Never Seez will work well for this application, and will prevent water intrusion.
Use a little wheel bearing grease.
Loctite won't be helpful here. It needs a very clean environment.
Use lock washers.

Issue: Engine started ok, but stopped when put into gear. Started again and ran 6 hours then it stopped again.
Check vent line on the fuel tank.
Look at the vacuum gauge for a reading.
Check the diaphragm on the mechanical lift pump.
Inspect for an air leak.

Query: Need to replace oil seals on Velvet Drive gear box. Any tips?
When you do the replacement, be sure to polish the shaft at the same time.
The job is not difficult.

Issue: There's a mystery squeak in the engine after changing the belt.
Use a tiny bit of liquid soap on the belt.
Make sure there's no air in the coolant system.

Issue: Engine overheats.
Check the elbow, strainers, and antifreeze/coolant.
Check for debris from impellers (Ursa Minor).
Switch to extended life antifreeze after flushing the system.
Check freshwater pump and also water heater bypass loop.
Check the thermostat.

Issue: Hydraulic shifting transmission doesn't always shift into gear properly.
Have a look at the hand lever. One cable may be loose. (Island Spirit)
Use ATF.
If the manufacturer's specs call for ATF, don't substitute something else. (Trumpeter)
Check the filter and clean it. Crud may be impeding a linkage. (C_Language)

Issue: Engine stays running after turning it off. The valve is closed at that point.
There may be some leakage through the valve. Clean the valve.
The problem may be algae growth.

Issue: Yanmar: there's a very small fuel leak around the copper washers.
Anneal the washers until cherry red, then give it one good tightening.

Issue: Yanmar; there's diesel fuel in the engine oil.
Check the injectors. Clean them.
Check seals on injection pump.
Bypass mechanical fuel pump and use an electrical pump instead.
Fuel return line may be loose or broken.
Fuel return may be plugged.
May need to replace the diaphragm pump.
May need to replace the injector pump.
Check the thermostat, it may be running on open.

Issue: Oil leak, also seepage around filter housing.
Pull out regulator, if possible. It may have a speck of something that needs cleaning.
Check o rings. Are all accounted for?

Query: How to locate the oil pressure sender? It's not in the user's manual.
Contact the manufacturer of the engine or the sending unit.

How can I test the oil pressure sender in place?
Check resistance from Terminal to ground.
There are two styles or designs of senders:
1.   0-240 ohms is the U.S. style.
2.   VDO is up to 1k and is the Euro style.
Test while running. If open circuit, sensor is bad.
Otherwise, range should be a few hundred ohms.
Pinhole in unit may be clogged.
Can replace with mechanical style gauge which is very reliable.
Get a new gauge from an auto parts store. Cheap.

Issue: Losing friction on oil change pump. Leather part is worn out.
Get new leather from a craft store and lube it with Sea Lube to make your own replacement. (Shining Star)
Make replacement out oil-resistant plastic.
Lube new leather before applying to avoid stretching later.
Mold leather by soaking it with water. Allow it dry thoroughly into it's intended shape, then lube it.
Use the pump body as a mold.
Use large piece of heat-shrink or a rubber grommet to help expand the surface as a temporary fix.
Re-lube the original leather to expand it.

Query: How often do you need to adjust valves?
Every 1000 hours.
Every two years.
When the engine doesn't sound right.
When over or under more than .002"
Snap-On stepped feeler gauges make the work easy. (Shamal)

Issue: Bracket holding reservoir on Yanmar broke.
May have been due to vibration; not an uncommon problem.
May have been a manufacturer's defect.

Issue: Loss of a small amount of coolant on a Yanmar; gaskets and connections are good and all is clean.
Check the reservoir for pin holes and replace it if necessary. (Soul Mates)
Water based ultraviolet light and dye will help locate a small leak. Can be found in auto parts stores.
Pressure test the system. This can be done while engine is cool. Coolant pressure tester is available at auto parts store.

Issue: Spline on transmission has a fluid leak.
Check O ring. Is it compressed?
Check air vent for clogging. Vent may be part of dipstick assembly.
A clog will cause internal pressure to increase, driving out fluid.
Try to run engine without transmission dipstick in to check for lack of pressure.
Use stuffing box material for sealing leaks, especially for hot spots.
Lube O rings with RTV silicone.

Issue: Volvo D240 engine blackbox malfunctions. Overheating. We're on our third blackbox.
Check for loose connections and make sure all are tight.
Volvo is aware that this is a problem.

Issue: Only half of the 3 quarts of transmission oil can be removed for replacement. It's a Volvo Model 1305A.
Search hard for a secondary plug.
Try to create a vacuum to pull the oil out.
Drain from the bottom when hauled out.
Manufacturer may only want half to be changed at a time.
Call Volvo tech support; their response time is good. (757) 436-2800.
Volvo suggests using a 'super sucker' to remove oil from this model.

Issue: Yanmar 56 solenoid has failed. I've already replaced it.
There may be a short in the wire.
Temp solution - hot wire the solenoid to the engine.
Update: Success. Replaced with auto parts relay. 30 amps cost about $11. (Soul Mates)

Issue: One of the engines is becoming harder to start. The fuel filter has been replaced. It doesn't seem to be a fuel problem and injectors are ok.
Check glow plugs.
Try to start it with throttles wide open, this may fix a sticky governor.
Clean the governor.
Pull injector out and reconnect to fuel line, crank engine to see if fuel comes out.
Check muffler and elbows for blockages.

Volvo no longer provides tech support. The phone number is now for dealers only. If you call, they will defer you to a dealer.

Check props for fouling as part of transmission diagnostics. Our reverse stopped working. The problem was due to a thick line wrapped on the prop. (Fiscal Stray)

Check the mounting nuts periodically. If loose, they can wreck the mounts. (Kismet)

Make sure all parts are accounted for. One of our pistons was destroyed when a nut was aspirated into the engine air intake. (Barefootin)

Check bolts on generators and engines periodically.

Check crankcase breather tube occasionally. If clogged, it may cause oil leaks. (Shamal)

The crankcase vent can be plumbed through an air cleaner to reduce oily residue in the engine room. (Dyad)

PYI carries good motor mounts. Recommends replacing every two years. (Moira)

Teleflex morse control cable. Has a 4" bend radius, with better characteristics than old cables. (Dyad)

ATF Transmission fluid from WallyWorld. It stays clean and useful for a long time. (Valkyrie)

Transmission fluid can breakdown quickly with just a small amount of contamination. (Scotch Mist)

My get-home solution for transmission slippage (due to clutch plate wear) was to mix STP at up to 40% with ATF type A. (Ursa Minor)
[Note: Use with caution, not as standard practice.]

STP can be used to slow transmission leaks. Has been working aboard my boat for the last few years. (Mambo)

Quick fix for water pump failure:
Use the shower pump or deck wash pump. Make sure engine is running before using this fix. (C_Language)

Turbo Wash removes carbon from engines. (Alcid)
Manufacturer recommends using it every 200 hours. (Shamal)

When sloppy seas create too much air and foam in fuel, remove 2 of 4 injectors at their pipes. (Llamedos III)

Ultraviolet leak detector dye can be a good diagnostic tool for oil leaks.
Also comes in other formulas such as for freon. (Dyad)

American Diesel Services (Destiny)

Engine Gauges pdf.   A doc about testing and installing engine gauges. The link is to download this pdf doc from Jamestown Distributors. (C_Language)

(also cooling systempaint for engine partsrunning gear


Query: How to prevent carbon buildup on the transom? I've already checked the elbow and the injectors.
Use Marvel Mystery Oil at 4/10th oz. per gallon of diesel. It really helps. (Discovery)
PS Systems is a good product. It keeps injectors clean. (Kumbaya)
Check the exhaust thru hull for obstructions/restrictions. Occasionally run the engine hard, to blow the carbon out. 18 hp = 1 gal/hr. (Dyad)
Run at high rpm, neutral before shutting down. (Cat Tales)
Ditto. Agreed. This is a procedure Yanmar suggests. (Passages)
Make sure the engine is running at an appropriate temperature. (Salty Paws)

Issue: Black sooty exhaust. The soot actually floats on the water.
Check the valve clearance.
Check for fouling on injectors. And clean with a fine brass wire brush.
Examine spray pattern. It will dribble if not closing properly.
A drip will eventually score the cylinder.
Fix this immediately or it will damage the piston.
Check cold start apparatus.
Update: Success. Problem solved by valve adjustment.

Issue: White smoke on Yanmar under load and no load.
Valve guides may be the problem.
Increase crankcase pressure by plugging the vent to test for oil leakage through guides.
White smoke indicates water or excess fuel in the combustion chamber.

Issue: White smoke from engine exhaust; oil and water temps are okay.
It could be water. Check gaskets.
May need to replace gaskets.
Check injectors and tighten.
Check the impeller.
Check oil level after every run.
Check coolant flow; it may be low.
Check exhaust elbow, it may be plugged.
There could be a clog in the strainer.

  Typically on a cold start, a diesel will smoke white (unburned fuel). As the engine warms up, the fuel burn gets better and the smoke turns light gray. On some engines the transition is quite fast and barely noticeable. On Paydirt it is 2 or 3 minutes.
  If the smoking continues after warm up, check the exhaust for unburned fuel on the water (sheen). Or do like the old timers and sit in your dingy in line with the exhaust fumes. If your eyes itch and water like you got maced, it's unburned fuel in the exhaust. (This is actually very accurate in detecting a problem with the fuel burn.) If no fuel is present, then it could be coolant in a combustion chamber. Check your coolant level. Either one of these conditions need immediate attention as a "wet" cylinder will soon destroy itself. If it is neither of the above, then it may be a mis-diagnosis of the color, which is very easy to do. It may be oil causing blue smoke. If oil consumption is in a normal range it is not usually an emergency repair. If it is higher, repairs are needed.
  Diagnose the smoke first, then start breaking it down from there. (Paydirt)

(also impellers,  injectors)


Query: Would a repaired (re-welded) exhaust manifold be as good as a new one?
If the new weld looks good and is not grainy, it should be just as good.

Query: Where can I purchase custom stainless exhaust elbows?
Search e-Bay.
Go to McMaster.

Blow through it to check for obstructions. (C_Language)

One indication of blockage is visible steam coming out as exhaust. (Slow Mocean)

Test periodically with a temperature gun when running on known rpm. If there's a change in rpm, start looking for blockage. (Pay Dirt)

Query: How to clean them out?
First get the temperature up by running at top speed/full load for short periods. Get it hot. Use muriatic acid for a flush cleaning: fill the sea strainer with the acid, let it sit, then run engine for 30 seconds.
~ or ~
Begin with a cold engine. Place 1 cup of muriatic acid in raw water pump, run for 30 seconds, then let sit for a few minutes.
Remove the elbow and soak in a bucket of muriatic acid.
Paint to prevent/slow future build-up. Use POR paint. Pour in/pour out just to coat. Lasts a long time, but may not be effective on weep holes.
Check for the cause of the build-up.
If you've been running at idle for long periods, deposits may be salt instead of carbon.
Some manufacturers advise not to use acid because it could pit the finish (possibly cya advice) while others keep its use as a trade secret.

Stainless steel exhaust elbows won't last long because they use oxygen to passivate and protect it from corrosion. Use galvanized steel instead. (Hold Fast)

If your elbow has an aluminum fitting, check the inside of it for corrosion. The aluminum may seem fine on the outside, but it tends to corrode from the inside out.

Pendaflex file spines can be used to clean out exhaust elbows. These are the metal bands found at the top of hanging folders. They're strong steel, yet flexible. (Salty Paws)


Query: How to make a temporary get-home fix on a leaky exhaust hose?
Use Marine Tex first.
Reinforce weak spot with a split aluminum can.
Use duct tape and hose clamps.

Both Vetus and Shields carry quality exhaust hoses.

Do not use carbon steel reinforced hose. The cut ends corrode causing problems.


Good inexpensive polarized sunglasses can be found in the sporting goods section at WallyWorld. Bypass the main sunglass display in the front of the store. (Salty Paws, Dyad)

You can find sunglasses that have sun protection on the upper part of the lens and magnification with light gray near the bottom. Bass pro shops carry them for about $60. (Shining Star)

Dive shops carry bifocal inserts for sunglasses or snorkel masks. (Blackfoot, Salty Paws)

Use Loctite on the hinge screws. (C_Language)

Make your own strap for eye wear out of blue tape by folding it over on itself. It will last for about one season. (C_Language)

Used up dryer sheets can be used to clean eyewear.(St Jude)

Zenni Optical purchase prescription eyewear online. Quality, fast delivery, inexpensive.



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