Onan 15.0 MDJF Generator injector pump fuel leak

[Salty lady]

I’ve taken the injector pump to Metro injector service in Conn. They are a large rebuild shop with shops all the way to Fla. It’s a rotary pump that they can’t find parts for anymore. The fuel is leaking out the throttle shaft. Does anyone have a parts machine that I could buy or another place to take the pump to.
If I have to replace the unit has anyone put one in under the galley floor with out tearing the boat apart to get it in. I would think about putting in a lower kilowatt unit ,smaller physical size to make installation easier. Will post picture of pump when I figure how.

Salty Lady 53’ MY 1979. #555
In Conn leaving for Fla soon

 

[jim rosenthal]

Most of them that were replaced seem to have been swapped for a NL unit. I think they are overall a bit smaller. Parts are much more available from all I have ever heard.

 

[Captain Ralph]

If your looking for the ole Stanadyne pump, good luck.
As lots of parts for the oldies just are not available anymore.

We have removed a couple of those Cummins/Onan MD3 & 4 sets.
Mostly due to lack of repair parts.
The MD has to be torn down in pieces for removal (to the short block).

The electrical end and pan come apart for the NLs going in.

Study the under floor carefully from the generator room. Some are designed to come up and offer larger access to those old monsters.

Replacing the OhNo 15 is going to be a tough call with the new set going in.
NL 12KW is a nice 3 cylinder unit, the next size is a 4 lung 16KW unit.
I would recommend the 16kw, holds about twice as much engine oil.

 

[Salty lady]

The pump is a PSU. What is the model Onan that you refer to 12kw?
Thanks for all the input so far

 

[Captain Ralph]

The pump is a PSU. What is the model Onan that you refer to 12kw?
Thanks for all the input so far

Sorry, I poorly just typed NL, I should of typed out Northern Lights.
I was referring to the Northern lights 12 or 16KW as replacements for your 15KW if you were going to replace it.

 

[Hat52MY]

If you are going to replace the GenSet, work on ordering the new one NOW. There is a shortage on GenSets in the market currently and lead times are long. BTW, I second the Northern Lights (NL) as a replacement for the Onan. I swapped my Onan MDL4 (20KW) 2 Stroke for a new NL 20KW 4-stroke. The weight difference between the two was within a few pounds and a slightly smaller footprint. We have been very happy with the new quieter and peace of mind knowing parts are readily available should they be needed.

 

[Avenger]

I have a rebuilt pump on the shelf, or I can probably find the part you need. Shoot me a PM if you're interested.

 

[Salty lady]

Avenger. Sorry not tech savvy. Couldn’t figure how to pm. Will get a friend to help tomorrow. Very interested to talk with you about pump or parts.
please email me at saltcityboston@gmail.com
Thanks Salty Lady 53’ my #555

 

[Avenger]

I'll send an email when I get to the shop on Monday and we'll figure this out.

 

[jim rosenthal]

I have that Northern Lights 16 kW set as the standby at my house in Annapolis. They are outstanding gensets, I don't think there are any better. I have a smaller one on my 36' Hatteras.

 

[SKYCHENEY]

I have that Northern Lights 16 kW set as the standby at my house in Annapolis. They are outstanding gensets, I don't think there are any better. I have a smaller one on my 36' Hatteras.

But Jim, I really think all of these marine generators are pretty much the same. What you need to look at is 3 things:

1) What engine are they using (Yanmar, Kubota, Nissan, etc)

2) What generator end are they using (Martin, General, etc)

3) What controls are they using. Are they off the shelf regulator boards that you can buy online for $20 or are they some proprietary board that will cost you $$$$ to replace?

None of these guys make these components. They just assemble them. So, look at how that's done. Do you like where they mount the raw water pump, heat exchanger, etc and make your selection. I tend to discount those that say NL is best or Kohler or whatever. I'd rather have something that I can keep going with off the shelf parts. Its the total cost of ownership that matters and the ease of service. Obviously, those that use quality components and do a good job with assembly end up having a good reputation, but I'm not sure there is really that much difference from one to the next.

 

[jim rosenthal]

I think you're right- most genset manufacturers are assemblers. Maybe Onan make their own engines, I don't know.

The engines in the NL sets I have (and my 16kW set is basically identical to the 16kW set that is in MikeP's former 53 MY, except mine is radiator-cooled and his is HE cooled) were built by ISM/Shibaura. I believe that ISM/Shibaura also build all those refrigeration units powered by small diesels that you used to see on reefer trucks. I know of NL sets on commercial vessels that have documented over 20K hours running before an overhaul, with routine maintenance. NL sets were on commercial vessels before they were popular with yacht builders, I recall hearing. I really do think they are the best out there. Then again, it's been decades since I owned anything else, to be fair.

 

[SKYCHENEY]

20,000 hours should be about right. I have a 3 cylinder Yanmar on my genset. I have the same motor on a dewatering pump at the quarry. We have rebuilt that motor twice. Both times it had almost 30,000 hours on it.

Generators are not pushed past their limits like main engines are. They should get the same number of hours between rebuilds as most industrial engines if they are used and maintained regularly.

 

[Blowncar]

Stab in the dark, you say the shaft is leaking? My onan 20kw had a similar problem and I fixed it by replacing the shafts o-rings , cost 40 cents.

 

[Salty lady]

Thanks but I sent the pump to Avenger. Turns out he has a rebuild shop in Long Island NY

 

[doc g]

Since we are talking about Oh- No parts anyone know where I can get a flywheel for for MDL4 20 kw onan?? I have friend who needs one. also if anyone what industrial engine is on that unit that could help too....................Pat

 

[jim rosenthal]

Good point about generators not being asked to go beyond their limits; they have circuit breakers etc.

 

[SKYCHENEY]

Since we are talking about Oh- No parts anyone know where I can get a flywheel for for MDL4 20 kw onan?? I have friend who needs one. also if anyone what industrial engine is on that unit that could help too....................Pat

I know there is a take out sitting at Crosswinds Marina in Whitehall Michigan. He may part it out. Might be worth a call.

 

[cww]

I had this problem with the MDJC on my Chris-Craft, getting parts was so difficult that I was always trolling eBay or dealing with ancient supply houses in the pacific NW. Onan no longer supports the pre-Cummins merger models. Whenever it broke, just like you’re going through now, it took weeks to locate and get the part, and then it would work until the next thing broke and would be down again for another month. A generator with 50% downtime is a crappy generator.

I replaced it with a Phasor in the same size, 12kw, and have nothing but nice stuff to say about them. Super reliable Kubota Diesel engine, quality components. Best of all NO proprietary circuit boards or controllers, everything on it can be SERVICED not just replaced. Not that it matters because it never breaks, I put 600+ hours on it with nothing but an oil change.

My Hatteras has a northern lights in it that I’m sure cost 4x more, and I’m sure the name brand probably adds some value to the boat in the eyes of a buyer. But being honest here I just don’t see some big quality difference between the two. They’re both very well made.