Leaking injector pump MDJC Onan

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

Always Late

Veteran Member
Joined
May 27, 2020
Messages
96
Location
USA
Vessel Name
Always Late
Vessel Make
Marine Trader 44 DC
My 1980 vintage 12 kw Genset injector pump started leaking this week. It's been hard to find parts for a long time but the unit runs flawlessly. Hoping to find a whole pump or rebuild kit that someone has squirreled away in the bilge or garage.
[emoji1696]

Gary
 
If you don't have any luck here, check the forums at Smokstak.com. There's a few old Onan guys there that have been working on them forever and are likely to have some suggestions on where to get stuff.


Unfortunately parts supply has become an issue over the last 10 - 15 years for many of the old Onan models. I get the feeling that Cummins isn't a huge fan of the legacy Onan stuff and started discontinuing parts as a result. But the J series units (other than being a little bit crude and smoky) are a very solid generator as long as you've got parts. Same story with my old gas MCCK.
 
If it's a Kubota Engine, you might be able to find part numbers through them, and buy through their tractor dealers.


No such luck for that unit. The J series engines were an in-house Onan design.
 
Most ONAN diesels I have seen use a common Stanadyne injector pump. There's a plate on the pump. Any injector pump rebuilder should be able to rebuild your pump.
 
Mine leaked and it turned out to be the "o" rings on the injector pump lines from the the pump to the injector.
 
Most ONAN diesels I have seen use a common Stanadyne injector pump. There's a plate on the pump. Any injector pump rebuilder should be able to rebuild your pump.
This one is an American Bosch.
 
If you don't have any luck here, check the forums at Smokstak.com. There's a few old Onan guys there that have been working on them forever and are likely to have some suggestions on where to get stuff.


Unfortunately parts supply has become an issue over the last 10 - 15 years for many of the old Onan models. I get the feeling that Cummins isn't a huge fan of the legacy Onan stuff and started discontinuing parts as a result. But the J series units (other than being a little bit crude and smoky) are a very solid generator as long as you've got parts. Same story with my old gas MCCK.
Thanks for the suggestion, I had forgotten about smokestack.
 
Local fuel injection company has the parts to rebuild the pump and gives a 1 year warranty on the repairs! The old Onan lives to see some more cruising.
G
 
Back
Top Bottom