Stator failure?- Northern Lights 6kw

twistedtree said:

I tend to agree with Kevin. $6k must be approaching the cost of a new genny.

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new one is $13K

Be VERY wary of a $6,000 generator end replacement plus rebuild of the prime mover.

NL parts are not cheap. Expect the wholesale price on the generator end to be something over $2500 alone. Thats not counting labor, or the engine parts.

David Hughes said:

new one is $13K

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Wow, I stand corrected.

ksanders said:

Be VERY wary of a $6,000 generator end replacement plus rebuild of the prime mover.

NL parts are not cheap. Expect the wholesale price on the generator end to be something over $2500 alone. Thats not counting labor, or the engine parts.

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Agreed. $6k doesn't add up unless this is a slam dunk one day job with free and easy(read here on the shop bench like) access. Then again maybe you are that big of a customer that your shop is going to extend their parts discount to you and discount their labor rates. If that's the case awesome for you. I'd expect closer to $10k myself but good luck going forward and for your sake I hope $6k is correct.

$13k new sounds right in the strike zone for a NL replacement as I recently priced new marine genies.

David Hughes said:

new one is $13K

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I faced a similar situation a few years ago with my Kohler 9KW that failed due to a poor installation. A new 9KW Kohler was $9K.

Since I could see the cost of the rebuild approaching that number I went with a new unit.

I also looked at replacing my toasted Kohler with something else. I still have those quotes (unit only, no install):

Kohler: $9K
Onan: $13K
Westerbeke: $15K
NL: Almost $17K

It is there on the shop bench already. The stator is $2000 from Broward Armature. I suppose $6k is my optimism. I'm still waiting on the full quote. I suppose I'd take $8k versus $13K for a new one but not much more. A new one might be in my future.

David Hughes said:

It is there on the shop bench already. The stator is $2000 from Broward Armature. I suppose $6k is my optimism. I'm still waiting on the full quote. I suppose I'd take $8k versus $13K for a new one but not much more. A new one might be in my future.

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Money things are never fun, but I'd hate to see you put six or eight thousand dollars in this unit, only to have to spend more sooner rather than later.

For me its simple. If the cost to fix something comes to 1/2 the new price I buy new.

ksanders said:

Money things are never fun, but I'd hate to see you put six or eight thousand dollars in this unit, only to have to spend more sooner rather than later.



For me its simple. If the cost to fix something comes to 1/2 the new price I buy new.

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I'm thinking the same thing...

David

In a another thread an owner is wrestling with problems stemming from a rebuild of a Cat 3208. As suggested, rebuilds for gensets have a price breakoff. A total genset rebuild by a certified NL shop offering an as new warranty may be worth looking at provided the cost is no more than the 60% range.

Don't forget to insure adequate fresh air and leak proof surroundings though.

BTW, was it ever determined where the water came from that ruined it in the first place?

twistedtree said:

BTW, was it ever determined where the water came from that ruined it in the first place?

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I'm waiting for that answer too!

David, I'll tell you a little story regarding rebuild Vs buying new for generators.

Two decades ago I had the bright idea that I could start a business rebuilding prime power generator sets and selling them. I envisioned an exchange system where I could take in a core and supply a new-rebuilt unt in exchange. In Alaska there are LOTS of small prime power generators in use. In fish boats, construction, even in rural homes.

Sounds like a great idea right... Even greater since due to the nature of my work I only work "part time" at my primary career, so I woudn't have to live off of the revenue.

What I quickly learned was that if I did a great job on the rebuild I could not pay myself market labor rates and remain price competitive with a new off the shelf generator.

That was 17 years ago, and I don't think anything has changed since then.

This endevor was not all wasted though. Through the process I identified a undermarketed nitch area in high capacity power switching and measuring equipment, which fit right in with my background. I am happy to say that the company I formed (which will remain nameless) has grown to a point where we are a dominant player in this market, with great brand name recognition and market share, in this nitch arena.

So..

When I caution you to be wary, it's because I know what it costs to do the job right, and that cost does not favor rebuild Vs replacement with a new unit.

Thanks for that wisdom! I really appreciate the insight. I'm already leaning toward new. Could I get away with the $8000 Kohler versus the $13,000 NL for light use of running Air Con probably 20 nights in a year?

David Hughes said:

Thanks for that wisdom! I really appreciate the insight. I'm already leaning toward new. Could I get away with the $8000 Kohler versus the $13,000 NL for light use of running Air Con probably 20 nights in a year?

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Of course! Northern Lights is just one of several generator packagers out there. I do not want to miss out on naming sombodies favorite brand but names I know are Onan, Kohler, Westerbeke just to name a few.

There are smaller packagers out there like Norpro, Nextgen, and the like as well.

If you are someone that prefers to have your unit professionally maintained, pick a brand that has good service support in your area. If you intend to cruis longer distances I'd pick one of the major brand names simply because you'll find more parts and labor support for them.

I think it is vital that you determine how the engine got salt water in the cylinders. A badly designed (or executed) wet exhaust system is often the culprit. Lots of cranking but no start is another.

Don't forget to look at Phasor gensets too.

It never had a hard time starting. It did have the wet exhaust elbow and raw water pump replaced less than 50 hours time previous, so that is a most likely variable to consider. I doubt it would be design issue; but it could have been an execution problem, as you describe.

Gensets do have design issues that affect sea water intrusion through the exhaust. And they also have installation flaws that do the same. An example of each:

The NextGen 3.5 genset in my 2003 Pilot 34 originally had an exhaust riser (the vertical loop of the exhaust immediately after the exhaust flange on the engine) that was too low. It would let sea water back up into the engine when the boat was docked with the stern toward following seas. They redesigned the elbow to increase height and the PO replaced it sometime about ten years ago with the new one. No problems since.

A Northern Lights 5kw genset was installed in a sailboat that I previously owned. It had a lift muffler and an exhaust that looped up as high as possible and then down to a transom exit. Once which sailing downwind in high winds and seas, water backed up over the loop, filled the lift muffler and finally backed up into the engine.

The fix was to relocate the exhaust to the side.

Take a look at the two pics attached. One is a diagram that shows the minimal height needed for a riser above the water line- 12". The other shows an inherently safe design using a water lift muffler. Both courtesy of Tony Athens from boatdiesel.

David

If water got in the cylinders, but engine was not run with wet oil, a full rebuild is likely not needed. Crank, cam, injection hardware should still be pristine. Pistons may be recoverable if you can get them out without damage. Cylinder walls may cleanable. Valves should be replaced even if they clean up. Cylinder head may need to be replaced because they cheaped out and put NO removable seats in exhaust!! Headscratcher there.

I have the same unit on my boat. Got it out of a sunk Bertram with 3600hrs on it. Now has another 2000hrs since.

I agree the money side may favor going new. It is almost always worth it to fix one end of the genny or the other. But when both go bad that gets expensive.

I think the NL is a good unit, but it is not worth twice the price of the other brands.

Do look at Phasor, Nextgen, Norpro. But stick with 3cyl and I don't think any of those are quite as compact as the NL at 5-6kW.

Water in generators paid for the construction of my boat. Mostly. Something I know a bit about. With NL charging so much, it was often worth fixing them.

Thanks for more great guidance. I'm talking with the repair place and getting their quote this week. Big issue whether run hard with water in the oil at the end. I'm afraid that happened.

If it ran with water in the oil, the oil will be emulsified milkshake.

If it was not run, water will be separated on the bottom of the oil pan, the oil on top will look normal. Valve gear viewed through oil fill cap will be shiny grey metal with no hint of moisture or milkshake.

If you see milkshake, it has been run and that will increase engine damage.

Running with sea water in the oil won't necessarily trash the engine. Ski will probably remember this story as it was discussed several years ago on boatdiesel.


Four years ago, I shipped my Pilot 34 from Connecticut to NC. When it arrived at the yard, I attempted to start it on the trailer just to make sure before launching. Well it rolled over a 1/2 turn and stopped. I then put a wrench on the front pulley and attempted to turn it over by hand. It turned hard at first and then seemed to free up. I didn't know any better and started the engine and it ran fine for about ten seconds, then we launched it.


I got back it to my home dock, a half hour away and the next day took it out and noticed water condensing out of the blowby tube. That didn't look normal to me so I pulled an oil sample and a few weeks later the results showed high sodium- 722 ppm with potassium of 25 ppm. Ski advised that this was probably not antifreeze as Blackstone indicated in their report, it was likely sea water as the natural seasater sodium to potassium ratio is 30:1 like what the oil analysis showed.


I theorized that when lifting the boat and loading it on the trailer in Connecticut or during its ride down the road, sea water sloshed up into the engine. It was just enough to hydrolock one cylinder but I was able to push the residue through the rings when I barred the engine over. I calculated (hey I am an engineer) that the total sea water was a cup or two that passed into the oil.


So I drained the oil, changed it twice and it has been good for the last 200 hours. Most of the water was driven out in blowby condensate and I never saw mousse or rusting of the valve train. I probably put 2-3 hours on the engine over a 2-3 week period between launching and the oil changes.


When I hauled the boat two years later to ship it back to Ct, I had the lift operator lift the boat out of the water and while it was hanging, I started the engine and ran it for ten seconds to blow all of the water out of the engine and muffler. No problem this time.


David

The difference is sitting time. Dave, in your case you sorted it right away. Water in an engine can often lead to zero damage. But let it sit and seize up, that is different.

Well, while it was shut down immediately after it "blew up", the cylinders sat with salt water in them too long, and the windings also blew up because of the salt water spray in the sound box. That basically ****ed up the whole thing. Don't know where the salt water spray came from. A pump, a hose, etc.
point is a rebuild was going to be $6k, and a brand new Northern Lights 6kw was $9500. So a new one is ordered and will be installed next week. Another costly lesson in boat ownership....

OK, so this is a TOTALLY different cause of death that originally described. The original description was of a spontaneous melt down of the stator. But now it sounds like there was some sort of raw water leak and salt water contamination of the engine and stator. That will kill it all dead, for sure. But far from something you can blame of a faulty or poorly sized or designed stator.

twistedtree said:

OK, so this is a TOTALLY different cause of death that originally described. The original description was of a spontaneous melt down of the stator. But now it sounds like there was some sort of raw water leak and salt water contamination of the engine and stator. That will kill it all dead, for sure. But far from something you can blame of a faulty or poorly sized or designed stator.

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Totally agreed. The original story to me was of just the windings blown up, and in fact the motor would still start when the NL technician showed up. It was later, after removal, that the dealer told me about the salt water in the cylinders. Still no definitive culprit as to the source of the water. Don't think anyone on the thread ever blamed a badly designed, installed, or sized stator. It was more the mystery of what happened. Thanks for your comments.

Similar issue with 843....

So I found this thread and realize it's a few years old - BUT....

I have a M843 that smoked this weekend. Three weeks ago we ran it for two days without incident. The boat came back to the dock and has been there for the last three weeks without use.

This weekend I planned to change the oil on the engines and generators.

I started up the 843 to let it warm up. I then turned around to go start the 673. By the time I started that unit and turned back around (20 seconds maybe), there was smoke pouring out of the sound cover on the 843. I shut it off and turned on all the ventilation systems to clear the engine room.

I pulled the junction box cover off and didn't see anything apparent in there, so suspect the issues is down below in the generator end. This unit was dry, and sitting at about 70 degrees ambient temperature when I had started it. There was NO load on the unit at all.

I did not notice any water leaking anywhere near the generator, but didn't get a chance to see if the exhaust was pushing water out of the side of the boat.

I restarted the unit (after turning off the breaker to be safe) and no more smoke. I didn't check the voltages yet, but I'd bet there is no power coming from this generator.

So now I'll be in the same "Boat" as the OP. I plan to pull the gen end off this weekend to see what I can figure out.

To the experts on here, does the 843 also use a proprietary taiyo gen end?

Also, If I do find that water may have gotten in there, how would water get into this area? From what part of the generator? There are no other places nearby that water could get near the generator, so if it's present - would it be a head gasket or something like that to cause water to get there?

I’d call Scott at Northern Lights tech support in Seattle. He’s awesome.

The larger NL units all use Marathon generator ends.

If the generator end on my 9kw NL generator ever goes out I'll be putting a Marathon unit in it's place, if the bellhousing and flywheel are SAE standard sizes.

I think the 843 is Taiyo. Should be a tag on the gen frame that ID's the elec end mfr.

Yes, in most cases the gen end can be replaced with another brand, but control box, control box mounting, lots of wiring, mounts, etc, needs to be changed to do a swap. Not fun..

I'll check the tag when I get into the project this weekend. Hopefully not a stator or rotor...