1981 - Californian Onan Salt Water Pump

[Starwatch]

The water pump for my 30MDJA Generator (Onan 131-0267) is no longer manufactured and there are no parts or pumps available. In any case it was a very poor design as the mild steel shaft is prone to corrosion and starts to leak with minimal use.

Has anyone found a solution to provide a salt water pump for the Onan generator? The generator has very low hours so am reluctant to replace it.

 

[N4712]

The water pump for my 30MDJA Generator (Onan 131-0267) is no longer manufactured and there are no parts or pumps available. In any case it was a very poor design as the mild steel shaft is prone to corrosion and starts to leak with minimal use. Has anyone found a solution to provide a salt water pump for the Onan generator? The generator has very low hours so am reluctant to replace it.

Use a march ac pump directly connected to the generator with a appropriate breaker. We did this on our Camano and has worked perfect.

 

[Edelweiss]

The water pump for my 30MDJA Generator (Onan 131-0267) is no longer manufactured and there are no parts or pumps available.

Has anyone found a solution to provide a salt water pump for the Onan generator? The generator has very low hours so am reluctant to replace it.

There is one on Ebay for $870 right now . . . or you can do like I did for $150 and replace it with a brass 3/8" Jabsco pedestal pump. Mount it on the oppose end of the platform from the Oberdorfer engine circulation pump. Place a 4 or 5 inch pulley on it and with a longer belt, run both pumps off the engine crankshaft pulley.

My generator is a 7.5 MDJE and I believe it has the same raw water pump. I converted mine about 5 years ago. Takes a little ingenuity, but it works better than the old gear driven pump. Don't forget to fashion a cover plate for the PTO where the old pump was installed.

 

[N4712]

There is one on Ebay for $870 right now . . . or you can do like I did for $150 and replace it with a brass 3/8" Jabsco pedestal pump. Mount it on the oppose end of the platform from the Oberdorfer engine circulation pump. Place a 4 or 5 inch pulley on it and with a longer belt, run both pumps off the engine crankshaft pulley. My generator is a 7.5 MDJE and I believe it has the same raw water pump. I converted mine about 5 years ago. Takes a little ingenuity, but it works better than the old gear driven pump. Don't forget to fashion a cover plate for the PTO where the old pump was installed.

Personally I think it would be easier for him to just put in a march pump for $200 and and some misc barbs. But that's IMO, the OP could do whatever he wants.

 

[Starwatch]

Hi Oliver

I like your idea of an ac pump driven by the generator, solves the problem of turning the pump on and off as required. Do you have a suggested model number that you used for the march pump. I tried a dc electrical pump, but I had a problem when engine flooded with salt water as the pump I used did not have a check valve.

Starwatch

 

[N4712]

Hi Oliver I like your idea of an ac pump driven by the generator, solves the problem of turning the pump on and off as required. Do you have a suggested model number that you used for the march pump. I tried a dc electrical pump, but I had a problem when engine flooded with salt water as the pump I used did not have a check valve. Starwatch

We just used a standard march pump that was $200 not sure of the model as to the engine flooding, that's why you hook it directly to generator. Not sure about your generator level, but try to put the march pump below the waterline so you won't have to worry about priming it when you get hauled out. But I'm not sure if you'll need a bigger pump, the genny we have is only a 3.5 KW so I think you might need a tad bigger.

Here's a link to a 500 GPH, I would think that should be enough.

Some please chime in if I'm wrong.

 

[Duvie]

spare pump

I bought a spare 7.5 MDJE with a bad generator section shortly after I bought my Californian. It has a different water pump set up than I have on the boat. It seems to be gear driven off the engine. It also came with a spare (used) saltwater pump. PM me if you are interested in replacing what you have. I would let the spare go for $100.

 

[Starwatch]

Hi Duvie

Thank you for your offer, but the reliability of the pump design is so poor that I would sooner invest the money into an electrical pump.

Starwatch

 

[grahamdouglass]

I have an onan mdja 3kw genset with a leaking seal

How did your raw water pump replacement go? Did you find and electric pump that would work? What make and modle did you finally find?

I'm thinking all you need to do is get an 120V electric pump with 3/8 ports. You could connect the power to the generator output and just connect the ports to the raw water intake. You could also mount the pump on bulkhead and not necessarily on the pump.

I'm not too sure of the gpm requirements of Onan 3KW MDJA generator.