Engine stalls when raising or lowering anchor

[Building a boat]

Hello,
I have a weird issue which has me and the mechanic and several people I have asked stumped.
I have a 1998 Hunter 310, it has the original Yanmar 2GM20F 18hp engine in it. 2400hrs on engine. I have a single cranking battery for starting and 2 6 volt batteries for the house.
Anchor is wired to run off the house bank.

Issue is whenever I go to use the anchor, if the engine is only idling the engine stalls. Normal idle on tac is about 1000RPM, set by mechanic. I can rev engine up and use anchor, but slow down to change gear it stalls, so slowly down from a fast reverse or forward and engine stalls if still letting out or raising.

When engine stalls, it starts up right away, no hesitation, no smoking, runs perfect heat at full revs for long periods. Mechanic says engine is running great and I kinda agree.

I did some voltage tests with smart meter.
engine running - batteries at 14.2 v. When I raise anchor (rated to draw 80amps)
1600rpm, 20amp draw from batteries, alternator supplies 55amps
1200rpm 35-40 amp draw from batteries
1000rpm 55 - 80 amp draw from batteries. Engine stalls.
We just redid governer, all springs and such, cleaned air filter. Have redone fuel filters twice.
Anchor raises and lowers fine with motor off.

Ideas ????????

 

[JamesG161]

This is a guess...

On my 1998 H430
1) The Start Battery supplies my Anchor Windlass power through a 75 Amp Breaker.
2) With engine running, the Alternator charges the Start Battery, only.

Your Start Battery needs Cold Cranking Power for engine, as does the Anchor.

Deep Cycle battery may work alone.

You may have a device that is trying to charge both Batteries at the same time, when the ignition key is turned on. Mine did, but the Ignition Key device is not functional

Jim...

 

[Davidasailor26]

Just a guess but have you confirmed the engine RPM’s with an optical tach or are you relying on just the engine’s tach? The engine tach could be off, leaving the idle lower than you think.

 

[Sefuller]

I am not familiar with the Yanmar engines, but it seems like the problem almost has to be electrical in nature. Is there an electric fuel pump or electronic kill switch on the engine? Those are the only things I can think of off the top of my head that may be somehow affected. In either case, or in general I would probably start by taking apart every windlass wiring connection and clean it well, and especially check all the grounds, then do the same for any electrical components on the engine that contribute to it's ability to run (or shut off).

I'll be interested to hear what the solution is.

 

[NYSail]

Pardon my ignorance here.... maybe I'm wrong / missing something but once the diesel is started, the engine (older model) does not need electric to run. Am I missing something? I have seen people with completely dead batteries jump the engine and motor back home. Alt puts out enough to power instruments but the engine because its compression based will keep chugging along. So why would the windlass cause the engine to stall?????? Maybe an electric fuel pump and overloaded batteries and it shuts off. Do your instruments flicker as well?

Greg

 

[Don S/V ILLusion]

Pardon my ignorance here.... maybe I'm wrong / missing something but once the diesel is started, the engine (older model) does not need electric to run. Am I missing something? I have seen people with completely dead batteries jump the engine and motor back home. Alt puts out enough to power instruments but the engine because its compression based will keep chugging along. So why would the windlass cause the engine to stall?????? Maybe an electric fuel pump and overloaded batteries and it shuts off. Do your instruments flicker as well?

Greg

You missed nothing.

 

[jviss]

My guess is that the windlass is putting a big load on the alternator, and that's what's loading the engine, slowing it down and stalling it.

A test would be to turn the key off with the engine running, and then operate the windlass, and see what happens. (I'm assuming this engine is not shut down via a fuel cutoff solenoid when you turn the key off.)

 

[leo310]

I agree with Jviss that your windlass is causing the problem. What I would do is check the wire at both ends . When was the lass time you checked your brushes on your windlass and re-lube it? It could be that dirt/salt is causing the windlass to have a extra load/power draw.

 

[jviss]

By the way, I always run the engine when using the windlass, and rev it up to at least 1,000 ROM (idle is 700); sometimes 1,500 RPM. But, mine won't stall, even at idle, when I run the windlass.

 

[Building a boat]

Wow , thanks for all the great ideas will try and work through them.
Greg, you think you got a lot of ????????, I have twice as many. ;0)
Engine has a mechanical fuel pump, checked that.
Tac wise, actually advanced idle couple hundred rpms and still had problem. Can't keep engine at high RPM, example coming up onto anchor need to go slow RPM, if too slow ak idle, engine stalls. Come up quick, stall when shift gear to neutral .
Engine is stopped via a pull wire, I have been warned if I turn off key. Alternator may burn out(no load ?) Different issue
Instruments do not flicker, chart plotter everything keeps going.
Battery connections clean, will double check windlass connection.
Engine off, anchor retrieves quick nicely.
I like the idea of moving to starter battery, I always run engine when anchoring.
Will double check load when engine off, but pretty sure it is approx 80 amps, lewmar spec is 80amps for this windlass.
Will post again after more tests, thanks again for your thoughts
Ryan

 

[jviss]

I have been warned if I turn off key. Alternator may burn out(no load ?)

That's not so. Turning the key off will just shut off the field current for the alternator, and it will spin, no-load, i.e., it won't put out any current to the batteries, and will just present its rotating friction to the engine.

 

[JamesG161]

I got this Page from the H310 owner's manual.

Does this match your boats wiring?

Jim...

PS: Note the Battery Selector Switch

 

[odaydokay]

Just a guess but have you confirmed the engine RPM’s with an optical tach or are you relying on just the engine’s tach? The engine tach could be off, leaving the idle lower than you think.

This is what I was thinking in addition to what is the mfg. idle speed spec? You could also try up-throttling the engine just a bit and see if it still dies during the anchor activity. These are both cheaper solutions than starting to tear stuff out.

 

[JoeWhite]

Is the alternator connected to all batteries permanently? Using battery switch can you disconnect the alternator from house bank? If so then do that and see if the engine idle drops when using the windlass. This would indicate the alternator is carrying a large load.
Are the house batteries in good shape?
Did someone replace the OEM alternator with much larger current output capacity?

 

[JamesG161]

Using battery switch can you disconnect the alternator from house bank?

This is what I asked.

I think he does not understand his Battery Selector Switch.

I posted the Windlass layout from the H310 manual in my post#12 above.
Jim...

 

[Will Gilmore]

I know absolutely nothing about engines, but I like a good puzzle.

I can rev engine up and use anchor, but slow down to change gear it stalls, so slowly down from a fast reverse or forward and engine stalls if still letting out or raising.

This only happens when using the windlass? Never when just coming down from high idle or when going in and out of gear to neutral and/or reverse?

Could the fuel pump be connected to the windlass electrical system? 20amp draw is a significant portion of your 55amp alternator. If your fuel pump isn't running as efficiently as it should be, maybe it boggs down at low RPMs.

I don't know how these things go together. I assume there's a pump in the tank, but if it's part of the engine, maybe not. What tells the pump to supply more fuel? Or does it just supply fuel and its up to the throttle to allow it through?

-Will

 

[Benny17441]

The only relation between the engine and the problem you are having would be an electric fuel pump. If it were a random occurrence it could be due to a loose or dirty connection but if it happens every time it is likely a voltage drop. Run a load test on the batteries to insure their health. A battery can show 12.7V, fully charged, just to have a drastic voltage drop when presented with a significant load. The 14.2V reading is likely from the alternator output and not reflective of battery conditions. If the batteries are charged and healthy then check the size of the wiring vs. the round trip distance from windlass to batteries. Older wiring can also develop higher Resistance but first make sure all connections are tight and clean. Many sailors with windlasses opt to install a dedicated battery up by the bow close to the windlass to avoid voltage drops in long runs, and just run charging leads to the battery. Also there is the possibility that the fuel pump and /or the windlass motor could be wearing down and posing an increased load than it/they originally did. Just occurred to me, make sure that fuel flow is not impeded by dirty filters and screens which could have the pump working at its limits. In order of Probability, 1) Bad Battery, 2) dirty connectors, 3) wear and tear on fuel pump or windlass. Good luck.

 

[jssailem]

Disconnecting the battery bank from the engine while running is not a recommended test procedure. Sure way to fry the alternator.

Use a DVM and watch the voltage as the windlass is switched. If this drop to 10 then your not producing enough energy to maintain the windlass draw and the batteries. Big downs the alternator and retards the belt. That could be enough to stop the engine Or at least make the belt squeal.
Check the batteries to see their state of health. Check all the contacts. The Contactor for the windlass could be failing. The contactor could have corrosion on the contacts.

 

[jviss]

Could the fuel pump be connected to the windlass electrical system?

The only relation between the engine and the problem you are having would be an electric fuel pump.

Engine has a mechanical fuel pump, checked that.

So, that settles that. Not the fuel pump.

@Will Gilmore said a bunch of things the communicate a misunderstanding about how diesels work, but without fisking his reply, here's some background.

The diesels typically found in boats like this are completely mechanical, ie., the high pressure pump, fuel injection system, etc., are all mechanical, and the only electrical accessories are the alternator, starter, maybe an electrical fuel cutoff solenoid (though this one doesn't have that):

Engine is stopped via a pull wire

Maybe there's an electrical fuel lift pump, at or near the tank, in case the run to the engine is far or uphill.

If the lift pump fails or slows, it won't have an immediate impact on the engine, and might not even stall the motor. My Catalina 36 had one, and it failed, which was only noticed, sometimes, on starting. When running, the engine pump could suck fuel right through it.

Diesels don't have a throttle, at all. They have a high pressure pump that is controlled by a governor. The control on the pedestal that we call a throttle is really a speed control. It actuates a lever on the governor to set the engine speed. The governor increases or decreases the fuel supplied to maintain that set speed with varying loads.

I think the alternator is loading the engine enough to stall it when the windlass is energized.

What's odd about this is that I was thinking that such an engine couldn't have an alternator big enough to do that. But, what determines how much load an alternator presents is not the rating of the alternator, as in 35, 50, 75A, whatever, but the electrical load that is presented to the alternator, and the amount of current supplied to the field coil up until the point of saturation. So, ALL alternators can be 200A alternators for a short period of time, until they burn out! So, this situation is annoying for stalling the engine, but can also kill the alternator.

Another puzzle is why is this happening now? I presume things worked well from the start, and that this is a new phenomenon. Well, what can suddenly increase the amount of current a motor draws? A stalled motor, e.g., the shaft prevented from rotating, for one. So, if the windlass motor bearings have deteriorated and are presenting a lot of friction, binding, or if there's some other mechanical fault that increasing friction in the system, that will increase the current the motor draws. This motor is also at risk of burning up.

Do you have a clamp-on DC Ammeter? It's really a wonderful tool, and a good investment for a boat owner. If you get one make sure it can read DC Amps, as there are many on the market that are AC only. If you get one or borrow one, you can directly read current to the windlass under these conditions, and then also alternator output current under the same conditions (with helpers, of course). This will tell you a lot.

Save that, you can take that windlass out and start disassembling it to find out the condition of the motor bearings and brushes. You can run it on a bench and find out the no-load current, and see and hear how well it spins. And, you can check the rest of the windlass for free-running, see if anything's rough or binding.

Another thing that can cause the windlass' DC motor to draw more current is a short in winding. If you take the motor apart you can check the individual winding resistances and compare them to each other, and ideally to a specification. Or, you can take the windlass motor to an automotive motor shop and have them test it and even rebuild it. A rebuild would include testing and maybe rewinding the armature, turning the commutator and cutting back the mica, and fitting new brushes and bearings.

As I said previously, the easiest way to determine if the alternator load is causing this problem is to just shut off the key with the engine running, which will, besides shutting off the instruments, shut off the alternator. It won't harm the alternator, it's not like disconnecting the alternator load with the engine running, which can zap the alternator diodes. (I used to do this often, to get me smart alternator to re-start the three phase charging regimen, which put it quickly back from FLOAT to ACCEPT, because my ACCEPT stage was timed and too short.) When you do this the alternator will just spin with the engine and no electrical condition on the boat can change how much load is presented to the engine; it will just be the free-spinning friction of the alternator, practically zero.

If the alternator is stalling the engine, it's probably the windlass motor that's causing it. Stop using it until you sort it out, as you can end up ruining the alternator and the windlass. Also, look into your windlass circuit breaker, as I would imagine that should have opened in this condition.

 

[JamesG161]

Ideas ????????

Yes, Look at your Private Messages for more information.
Jim...