Northern Lights Genset Injector pump replacement

[fryedaze]

The boat I purchased a couple years ago has a 6KW Northern Lights M673L2 generator on board. The previous owner disclosed the generator had water intrusion on 2-3 ocassions. When he replaced the previous Panda generator he kept the Panda water muffler system. The Mechanic who did the last work on the generator told me that the water muffler was located too high relative to the Northern Lights exhaust and the issue the previous own had was if the generator did not start quickly it would suck seawater back into the generator via the exhaust. He moved the water muffler lower in the boat and since then the generator had appeared to run great. Starts almost immediately and runs very smooth however, the only thing I really every used it for was changing the batteries and light loads. A few weeks ago we were anchored out for several days so we actually tryed to load the generator by using the microwave and the AC. As the load increased the generator would load, bogg down to where you would expect it to die, the voltage supplying the invertor/charger would drop to ~70V, the invertor/charger would trip and the generator would recover. I followed the troubleshooting guide in the Owners Manual and did not find a solution. The marina has performed some troubleshooting and reported that the generator is only running on 2 or the 3 cylinders. They believe it is using oil however the smoke coming out of the exhaust is just a couple shades off white. They determined the injector pump is bad and 2 different shops said they could not rebuild the injector pump. A new one is around 1200. The questions are

1) My immediate thought was to just purchase a replacement injector pump and install it, however, the marina recommended very strongly that rebuilding the orginal injector pump was better because of a timing issue that I do not understand. Is there any reason why a new injector pump cannot be successfully installed.

2) Can this generator be successfully repaired and reliable for the long term or should I be tossing it overboard and replacing it. It only has about 425 hours on it at this point.

3) The marina was also concerned that the generator was using oil. Is the oil use just a function of the issue of only operating on 2 of the 3 cylinders or do I have a real issue.

Looking for recommendations with the key goal of having a realiable piece of equipment.

 

[ksanders]

OK, if the generator is only running of 2 of three cylinders, have you had the injector looked at? How did they determine its the injection pump?

If the injection pump is at fault, and if you put in a new pump it will need to be timed in order to function properly. This is not something a novice would undertake.

As far as the engine, seawater ingestion is extremely hard on them, but the injection pump generally would not be affected. Thats why I'm questioning the diagnosis. I could see an injector issue. I could see a valve, or cylinder issue, but not an injection pump, if we assume that the water ingestion is the root cause of the current trouble, which is of course just an assumption.

The oil use may be no big deal if its minor, or it could be a very big deal. Has anybody checked to make sure you do not have other issues with the engine from the water ingestion.

Northern Lights generators are very good units, the best. They are based on the Kubota engines and the newer ones use the Marathon Magnaplus generator end, the best made.

My advice to you is if a competent mechanic says its an injection pump, make him stand by his diagnosis. Have him have the injection pump rebuilt, but make it clear that if the injection pump isnt the issue, he eats the price of the pump, and his labor.

If he wont do that, hire a Northern Lights authorized dealer to repair the unit.

 

[C lectric]

If one cylinder is not operating the most likely cause is a faulty injector which should be checked first.

A smoke a couple shades off white could be white smoke or unburned fuel. A goofy injector can cause that by not producing a spray that can be burned readily and the fuel goes out and shows as white. If the white smoke is acrid smelling that is usually a sign.

The oil use could be glazed cylinders from your light load use. That can be a bane of generators. A serious load should be put on it frequently. It may not be practical every time but at least every few times.

Get the injectors checked and repaired first.

Then get a serious load of 75-80% on it and run it and see if the smoking will clear up. If glazed badly enough it may not do so or reduce but not go away completely. If you are lucky a serious load on once repaired may clear it up. In the future a load of 40-50% may be all that is needed to control the glazing.

But if all you are running often is the charger and a few lights then I suggest you figure out something different or even the best gens will glaze.

I will second that you may be better served with a generator knowledgeable mechanic. Unless there is a better explanation than the inj. pump, or how they decided that, then I think the diagnosis raises some questions.
It could be but to to jump from a cylinder out of commission straight to a faulty injection pump means they missed the most obvious source, a faulty injector.

 

[Conrad]

This sounds something like what we experienced when we purchased our boat earlier this year. The 9 KW NL genset was hard to start, and a close look indicated that there was not enough height difference between the exhaust elbow and the muffler. That was resolved quickly enough, and the suggestion was that water had been sucked back at some point in the previous 600 hours, and was possibly happening when we were trying to start it.
However, the problem persisted, and included not being able to put a proper load on the system.
It turned out that the fuel filter had a leak around the manual pump and was sucking in air, leading to our issues. Once the fuel filter assembly was replaced everything worked fine.

 

[fryedaze]

OK, if the generator is only running of 2 of three cylinders, have you had the injector looked at? How did they determine its the injection pump?

If the injection pump is at fault, and if you put in a new pump it will need to be timed in order to function properly. This is not something a novice would undertake.
.

The injector pump was sent out to a rebuild shop and they sent it back and said it couldn't be rebuilt. A new injector pump is $1135. Due to the unknowns on the water intrusion I am trying to determine if I just cut my losses and by a new gen set or sink more money into this one.
Good comment on the timing. The yard warned me about timing and a new pump.

 

[Baker]

I don't mean any offense, but it sounds like you have a bunch of rookies around there. Get somebody that knows what the hell they are doing!!! this should not be that big of a deal for someone that knows what they are doing. I would find a decent mechanic. Do not throw that thing out...YET!!!! This is a simple diesel engine issue....and likely an injector as someone mentioned. If you sucked up water, it could have very easily fouled an injector....hence your smoke issue due to unburned fuel and the inability of the engine to produce proper power. Ths should not be that hard to diagnose by someone that knows what they are doing!!!

 

[Forkliftt]

Ditto

Please post a picture of the FI pump. Can't believe it can't be rebuilt. I can ask my fuel system guy.

 

[Xsbank]

I'd like to add my .02 as well - a fairly large genset like you have could cost 10,000 or more, depending on how you install the replacement. Find a Northern Lights guy and just fix it - they make great gensets and as mentioned, this is just a diesel engine issue that should be relatively easy to fix.

Or find a Kubota dealer, someone who knows something about Kubota Tractors. Take a look at the engine plate and see what kind of motor that You really do have. N.D. also have a very good customer service line - talk to them!

Or drop it overboard and spend the 10,000 on a new one, no one will notice.

 

[Forkliftt]

Or spend $10K, drop it on a PALLET and ship it to ME!

 

[fryedaze]

Question: OK, if the generator is only running of 2 of three cylinders, have you had the injector looked at? How did they determine its the injection pump?
Response: The Marina did check the injectors and said that was not the problem. When the injectors were deemed functional they started pursuing other fuel supply issues and the injector pump was evaluated. They recently reported that the injector pump had a broken spring. Is it possible that the water in the engine somehow caused an injector pump timing issue and the spring failed which them becomes a result of the water ingestion.

Comment: As far as the engine, seawater ingestion is extremely hard on them, but the injection pump generally would not be affected. That’s why I'm questioning the diagnosis. I could see an injector issue. I could see a valve, or cylinder issue, but not an injection pump, if we assume that the water ingestion is the root cause of the current trouble, which is of course just an assumption.
Response: The mechanic that repaired the generator prior to my taking ownership indicated that the cylinders were not a problem, however, he was being paid by the previous owner so it might not be the complete story.

Comment: The oil use may be no big deal if its minor, or it could be a very big deal. Has anybody checked to make sure you do not have other issues with the engine from the water ingestion.

Response: No, as stated the generator has been starting great, running smooth and until recently when we loaded the generator by the desire to use the AC / microwave at anchor we have not had a reason to expect anything was wrong. It really was amazing that I could winterize the unit and 6 months later it would start right up.

Comment: Northern Lights generators are very good units, the best. They are based on the Kubota engines and the newer ones use the Marathon Magnaplus generator end, the best made.

Response: Agree, I was very pleased when the boat had a Northern Lights generator installed. When I had issues my first discussion with the yard mechanic was there cannot be anything wrong with the generator; “it’s a Northern Lights, we never have t work on them”.

Comment: My advice to you is if a competent mechanic says it’s an injection pump, make him stand by his diagnosis. Have him have the injection pump rebuilt, but make it clear that if the injection pump isn’t the issue, he eats the price of the pump, and his labor.

If he won’t do that, hire a Northern Lights authorized dealer to repair the unit.

Response: The yard sent the pump to two different shops to have it repaired. Both returned it stating they could not repair the pump. It appears purchase of a new injector pump is the next step however, sinking $1200 into an Injector pump plus the labor for installation / timing is exactly why I am seeking advice. Trying to decide if for example I should have the cylinder compression tested, heads pulled and valves inspected prior to making an investment into a new pump that might not be the root cause.

Thought???????

 

[ksanders]

Question: OK, if the generator is only running of 2 of three cylinders, have you had the injector looked at? How did they determine its the injection pump?
Response: The Marina did check the injectors and said that was not the problem. When the injectors were deemed functional they started pursuing other fuel supply issues and the injector pump was evaluated. They recently reported that the injector pump had a broken spring. Is it possible that the water in the engine somehow caused an injector pump timing issue and the spring failed which them becomes a result of the water ingestion.

Comment: As far as the engine, seawater ingestion is extremely hard on them, but the injection pump generally would not be affected. That’s why I'm questioning the diagnosis. I could see an injector issue. I could see a valve, or cylinder issue, but not an injection pump, if we assume that the water ingestion is the root cause of the current trouble, which is of course just an assumption.
Response: The mechanic that repaired the generator prior to my taking ownership indicated that the cylinders were not a problem, however, he was being paid by the previous owner so it might not be the complete story.

Comment: The oil use may be no big deal if its minor, or it could be a very big deal. Has anybody checked to make sure you do not have other issues with the engine from the water ingestion.

Response: No, as stated the generator has been starting great, running smooth and until recently when we loaded the generator by the desire to use the AC / microwave at anchor we have not had a reason to expect anything was wrong. It really was amazing that I could winterize the unit and 6 months later it would start right up.

Comment: Northern Lights generators are very good units, the best. They are based on the Kubota engines and the newer ones use the Marathon Magnaplus generator end, the best made.

Response: Agree, I was very pleased when the boat had a Northern Lights generator installed. When I had issues my first discussion with the yard mechanic was there cannot be anything wrong with the generator; “it’s a Northern Lights, we never have t work on them”.

Comment: My advice to you is if a competent mechanic says it’s an injection pump, make him stand by his diagnosis. Have him have the injection pump rebuilt, but make it clear that if the injection pump isn’t the issue, he eats the price of the pump, and his labor.

If he won’t do that, hire a Northern Lights authorized dealer to repair the unit.

Response: The yard sent the pump to two different shops to have it repaired. Both returned it stating they could not repair the pump. It appears purchase of a new injector pump is the next step however, sinking $1200 into an Injector pump plus the labor for installation / timing is exactly why I am seeking advice. Trying to decide if for example I should have the cylinder compression tested, heads pulled and valves inspected prior to making an investment into a new pump that might not be the root cause.

Thought???????

Given what you've now shared, I'd go for a new injection pump, but only if the mechanic making the diagnosis installs and stands by it.

Otherwise like I said before, get an authorized NL dealer to do the work, including rediagnosing the issue.

 

[Forkliftt]

OK Dave, that's a bit more information to use while making an informed decision. NL are a great generator. I have an 8K with a three cylinder engine. It is clear now that you have an injector pump that needs to be replaced. I suspect the cause has nothing to do with water intrusion (almost impossible)- but you still need to confirm the remaining engine is worth the investment. You had/ have the injectors out. Visually check for rust with a pen light on each injector mounting hole then have your mechanic run a dry -then wet compression test. He will know how to do this. If the results are up to spec (check online), then I would run a simple cooling system pressure test on your closed cooling system (has the AF). It should hold steady pressure of about 12 psi for about 5 minutes. If it drops, look for any external coolant leaks, repair and retest. If it doesn't hold, this could indicate a failed head gasket/ cracked head allowing coolant to enter the combustion chamber. If all this checks OK, you should be OK. The compression should be as high as NL says, and you are looking for a variance in psi over 10%. This would prove that the piston and rings are holding and the valves are seating correctly. Good luck and keep us posted!