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Need Onan Generator Help, Please

  • Thread starter Thread starter Bill Root
  • Start date Start date
  • Replies Replies 46
  • Views Views 16,904
12 V alternator for the genny with 12 V batt.
 
You just need to power the fuel pump. The Walbro 24 v consumes about 1 amp. You can buy a little converter for 30-40 bucks:

http://www.trcelectronics.com/Meanwell/sd-50b-24.shtml

I'm doing something like this to replace a 32v priming pump.

You don't want to get into converting the whole genny to 12 or 24, because now you are affecting the control board, glow plugs etc.
 
You just need to power the fuel pump. The Walbro 24 v consumes about 1 amp. You can buy a little converter for 30-40 bucks:

http://www.trcelectronics.com/Meanwell/sd-50b-24.shtml

I'm doing something like this to replace a 32v priming pump.

You don't want to get into converting the whole genny to 12 or 24, because now you are affecting the control board, glow plugs etc.

Thanks, George. This could be a good option.

If I continue to strike out on the replacement mechanical pump, I will have to go with an electric one. I do have two 12V 8D gel-cells in the generator room that provide power to, and are charged by, the inverter. However, how the inverter is set up is a definite mystery to me and I have been unable to find anyone, including the former captain who ran this boat, who can explain it. For that reason I am steering away from using those batteries for the genny. Next option was to use a separate 12V battery with a small charger to run the genny fuel pump. I really don't need one more battery to worry about though, so that's not ideal solution either. If the converter would work, it could be the best solution.
 
One more idea- you might call Mike Cobb at Capitol Diesel, or John Rubano at Gold Coast Power. They are both buyers and sellers of marine diesel equipment, and they may be able to steer you to someone who has parts for old Onans.

I concur with Jim (Fanfare) about Onan and their (lack of ) customer service. In this case it is particularly annoying because he doesn't need a new genset, he just needs a fuel pump. But I'll bet when he does need a new genset, he isn't going to buy an Onan, after this ordeal.

I have heard good things about Phasor, as well.

If this pump is a mechanical fuel pump, it may be worth taking it apart and seeing if it just needs a new diaphragm. Not hard to make one of those.
 
One more idea- you might call Mike Cobb at Capitol Diesel, or John Rubano at Gold Coast Power. They are both buyers and sellers of marine diesel equipment, and they may be able to steer you to someone who has parts for old Onans.

I concur with Jim (Fanfare) about Onan and their (lack of ) customer service. In this case it is particularly annoying because he doesn't need a new genset, he just needs a fuel pump. But I'll bet when he does need a new genset, he isn't going to buy an Onan, after this ordeal.

I have heard good things about Phasor, as well.

If this pump is a mechanical fuel pump, it may be worth taking it apart and seeing if it just needs a new diaphragm. Not hard to make one of those.

Thanks, Jim. I'll try those two contacts. You're absolutely right that when I do need a new generator, it definitely will NOT be an Onan.
 
In my point of view, it is a Cummins issue, not so much an Onan issue. That's a Cummins 4A2.3 engine on there. They did at one point have a transfer pump repair kit: CD0149214200. So I take we extend the ban to Cummins engines?
 
Bill - see post #6.
 
So a 24 year old Onan needs a fuel pump so that would preclude you from buying a new onan?
 
So a 24 year old Onan needs a fuel pump so that would preclude you from buying a new onan?

No he will never buy a cummins because they bought Onan and .....


I think it's the principle of it.
 
I guess. No one here ever wants solutions. And there is a simple one. But the experts would howl.
 
I guess. No one here ever wants solutions. And there is a simple one. But the experts would howl.

If he puts a tank on the flybridge and runs a hose to the genny gravity should do the trick. Just keep the tank on the bridge filled and you can run all night.
 
I like my Cummins engines a lot, and I've not had trouble getting parts for them. However, in the past I had Onan generator sets and getting parts for THEM was very difficult- when they were available, they were insanely expensive, and took months to receive. So when I bought a new genset for Blue Note, I got a NL- I figured if I bought an Onan, I shouldn't be surprised if parts availability was a problem. Better a NL, a Westerbeke, or a Kohler. I know there are satisfied Onan owners out there, but I wasn't one of them.

I did find that Oberdorfer and Depco had water pumps for old gensets (both the seawater and the circulator pumps). Fuel pumps are a different matter.

It's a mystery to me why a company which holds up its end so well on marine diesels doesn't do it on another product line. Two different divisions, maybe? I have no idea.
 
You could mount a 55gal drum on the roof with a float switch and put a 32v bilge pump in your main diesel tank and pump fuel up to it and let gravity feed the generator.
 
Maybe I didn't make my point clearly. It is a Cummins engine of which the fuel pump in question is a part. The problem here is with Cummins, not Onan. Just like on another brand that uses, say, a Kubota or Yanmar engine, something went wrong on the engine side you'd be looking to the engine manufacturer, perhaps with the genset assembler as an intermediary, but the engine manufacturer nonetheless.

Personally, I'd have no qualms buying a new Onan, they have a very large dealer and service network. And Cummins doesn't seem to make small diesels anymore, Onans use various other engine manufacturers now.

But Captddis has got the far more relevant point of view, let's get back to a solution.
 
Why overcomplicate things? [ I know it is the HOF] way.
1 BUY A 24 VOLT ELECTRIC PUMP
2 GET AN OIL PRESSURE MAKE SWITCH
3 CONNECT A TOGGLE SWITCH TO JUMP THE OP SWITCH SO YOU CAN USE IT AS A PRIMER
4You have four 8 volt batteries if you connect a fused wire from the pos of the third battery you have 24 volts. run that to the op switch conecct the other wire to dc ground. Enjoy you Onan for 20 more years.

I am sure steve D antonio or the other expurts will find fault but this has been done for years with no problems. Chris Craft used to do this for 12 v electronics.

OR continue to whine.
 
Why overcomplicate things? [ I know it is the HOF] way.
1 BUY A 24 VOLT ELECTRIC PUMP
2 GET AN OIL PRESSURE MAKE SWITCH
3 CONNECT A TOGGLE SWITCH TO JUMP THE OP SWITCH SO YOU CAN USE IT AS A PRIMER
4You have four 8 volt batteries if you connect a fused wire from the pos of the third battery you have 24 volts. run that to the op switch conecct the other wire to dc ground. Enjoy you Onan for 20 more years.

I am sure steve D antonio or the other expurts will find fault but this has been done for years with no problems. Chris Craft used to do this for 12 v electronics.

OR continue to whine.


No fuel tank on the bridge? That's genius. Thanks Dave.
 
Not sure if that's any simpler than my $35 solution (plus cost of the pump), but I like the idea. On the 56MY and others of it's flavor, where the genset is a long way from the 32v battery bank, running that 24v tap would be a PIA. The fuel pump doesn't draw enough to hurt the batteries that much due to a misbalance draw down, which is what gets the "experts" excited. I think that applies more in situations like I had with a PO using one of the two 8Ds in the 24 volt thruster bank to start the generator and power some light 12 volt loads, which kept killing a battery. I gave the genny and those other loads its own starting battery and all is well. At least one of the POs was nice enough 20 years ago to replace the old 32v generator with a 12 volt unit.
 
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You should never put a float sw. on a day tank to run a fuel filling pump. If the float stick..major spill, I wonder how Nordhaven fills their day tanks, as they use them to feed the main engine and would ned filling daily at least....no fun on the high seas with big waves ??
 
Not sure if that's any simpler than my $35 solution (plus cost of the pump), but I like the idea. On the 56MY and others of it's flavor, where the genset is a long way from the 32v battery bank, running that 24v tap would be a PIA. The fuel pump doesn't draw enough to hurt the batteries that much due to a misbalance draw down, which is what gets the "experts" excited. I think that applies more in situations like I had with a PO using one of the two 8Ds in the 24 volt thruster bank to start the generator and power some light 12 volt loads, which kept killing a battery. I gave the genny and those other loads its own starting battery and all is well. At least one of the POs was nice enough 20 years ago to replace the old 32v generator with a 12 volt unit.

Agree that if you have a source for a 35.00 power supply that is easier.
 

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