Onan 20KW generator

[Regal2800]

I just purchased a 1988 52' hatteras which has a 20kw onan generator. The model number on the engine itself shows L-423D but it sounds like it is the same as the MDL-4. Does anyone know about this? I spoke with Cummins Cal pacific today and they are telling me that the generator and parts were discontinued in 1991. How is this possible that they discontinue all service and parts to a generator 3 years after the engine was made? I have a leak at the pressure relief valve on the fuel pump and i can't seem to find a new o-ring to remedy the problem. Where can i get parts for this genny? This is a fairly small problem i can fix without Onan parts but what happens if i need a new head or i blow a piston. What about starter motors and injectors? Is it a throw away generator now? Any input on this would be great.

 

[Bayside Bert54]

I have a 1984 Bertram 54 with a ONAN 18.5 KW Model 15 MDJF-3CR/2268A

I use it as a backup as fortunately, the other genny was replaced with a 16.5KW new Northern Lights a few years back.

The Onan has 5500 hours on it and may have a rod knock. The general consensus by the shop was that parts are difficult to impossible to come by and that it's no longer supported by the factory. They still thought they could do a rebuild on it if I was willing to spring for the dough. I declined and will eventually replace it with another Northern Lights.

That said, a good shop can probably find many parts for it

 

[SKYCHENEY]

I have a 1985 20kw MDL4 that I replaced because of the lack of parts. The engine runs fine with about 4000hrs on it, but the generator end is shot. The unit is sitting in my barn. Let me know if you need any parts (or the whole thing).

 

[Ross Macdonald]

I don't know where you are located but there is a great Onan service person in Costa Mesa, Cal. It is Advanced Marine Power. The owners are Greg and Shellie Fountain. Shellie is an absolute wizard at finding old Onan parts. I have a pair of 1992 15 KW MDL3's and she was able to scrounge up some needed parts. Give them a call. If there are any parts out there, she can find them. 949 548-9791. Ross

 

[Regal2800]

I live about 45 min from them. I will give them a call and see what they have to say. thanks for everyones input.

 

[JuiceClark]

I don't know where you are located but there is a great Onan service person in Costa Mesa, Cal. It is Advanced Marine Power. The owners are Greg and Shellie Fountain. Shellie is an absolute wizard at finding old Onan parts. I have a pair of 1992 15 KW MDL3's and she was able to scrounge up some needed parts. Give them a call. If there are any parts out there, she can find them. 949 548-9791. Ross

I'm having a shop rebuild the injector in my old 20KW Onan-Cummins. It was leaking drops and needed to be rebuilt and the new/old stock ones I found were ridiculously expensive. Well, my local shop is having trouble finding some part with bearings that needs to be replaced.

After perusing all these old threads, I found this post with a # above. Well, it's still good! That shop in CA has the part and most other parts for our ancient gennys. At only 3,000 hours, I'd like to get a few thousand more before replacement.

 

[cww]

I'm having a shop rebuild the injector in my old 20KW Onan-Cummins. It was leaking drops and needed to be rebuilt and the new/old stock ones I found were ridiculously expensive. Well, my local shop is having trouble finding some part with bearings that needs to be replaced.After perusing all these old threads, I found this post with a # above. Well, it's still good! That shop in CA has the part and most other parts for our ancient gennys. At only 3,000 hours, I'd like to get a few thousand more before replacement.

Probably isn’t going to happen. I replaced a 2,000 hour onan MDJC on my last boat because of lack of parts. Generators routinely have random stuff that needs attention, normally it’s no big deal, but onan stopped supporting the pre-Cummins merger models. It’s a problem. Instead of something breaking and it’s fixed a couple days later, you spend weeks or months trolling eBay and Craigslist trying to find what you’re looking for. Then you get it running just in time for the next thing to come along and it starts all over again. Because of parts unavailability the best I could manage on the old onan was maybe 50% uptime. It wasn’t worth it. I put in a Phasor that I put 480 hours on with nothing but an oil change and is running great for the new owner. It’s just not worth it, especially in Florida where you need ac.

 

[JuiceClark]

Probably isn’t going to happen. I replaced a 2,000 hour onan MDJC on my last boat because of lack of parts. Generators routinely have random stuff that needs attention, normally it’s no big deal, but onan stopped supporting the pre-Cummins merger models. It’s a problem. Instead of something breaking and it’s fixed a couple days later, you spend weeks or months trolling eBay and Craigslist trying to find what you’re looking for. Then you get it running just in time for the next thing to come along and it starts all over again. Because of parts unavailability the best I could manage on the old onan was maybe 50% uptime. It wasn’t worth it. I put in a Phasor that I put 480 hours on with nothing but an oil change and is running great for the new owner. It’s just not worth it, especially in Florida where you need ac.

Hey, I'll be the lucky one! But yeah, if I can't get at least 30 hours in a row without another repair, a new one will have to come. I try not to replace things until irrepairably broken, but I get it. I'm just hoping to get further on the to-do list before I have to deal with something major.

The PO overhauled the entire genny, including a new exhaust riser and all kinds of stuff. Then, it sat for 6 years and so the leaks come.

 

[madhatter1]

What year is the cutoff on parts? Mine is a 2003.

 

[cww]

What year is the cutoff on parts? Mine is a 2003.

It was late 1990’s I think. 2003 you should still be able to get parts for no problem.

 

[ageless]

I just purchased a 1988 52' hatteras which has a 20kw onan generator. The model number on the engine itself shows L-423D but it sounds like it is the same as the MDL-4. Does anyone know about this? I spoke with Cummins Cal pacific today and they are telling me that the generator and parts were discontinued in 1991. How is this possible that they discontinue all service and parts to a generator 3 years after the engine was made? I have a leak at the pressure relief valve on the fuel pump and i can't seem to find a new o-ring to remedy the problem. Where can i get parts for this genny? This is a fairly small problem i can fix without Onan parts but what happens if i need a new head or i blow a piston. What about starter motors and injectors? Is it a throw away generator now? Any input on this would be great.

disregard