Generator on our 1977 24 Argosy MOHO

[mikeajana]

So I have a little time this week and am making some progress on our 24. She sat for 8 months at the local Onan shop and never got far enough in line to be seen. I just got the generator running myself, and it seems to work well, buT I would appreciate some advice.

Question number 1?
We have the Original Onan 4.0 BF C3R /1600 2B. There is a wire that provides power to the fuel pump and fuel shutoff valve. Mine is intermittent, and does not always provide what I assume is the prerequisite 12 volts. The Genset seems to be running fine, but I it "engineered" with a relay to provide power to the fuel pump (Amazon) and shutoff valve (antique original). Am I missing something? Not sure if the original wire provided something like overheat or low oil protection.

Question 2?
There is an awful amount of vibration for the genset. This is our first ever foray into Motorhomes or campers. The stock "rubbers" seem to be okay and the replacements from the Onan Parts places are utterly ridiculous. Any recommendations on budget upgrades? I've read a lot of posts, and the Onan part #402-0283 at $54 x2 is just not gonna happen. The 3rd bushing, 402-0284 at $12 is doable. Does the density of these bushing rubbers matter that much?

For my long term planning, we love the argosy style, but want to lighten the electrical load. We have all LED lighting inside already. We are in Florida, so AC is a must (at times) and so is a refrigerator (our current one is Maki, or Muerto, or maybe I just can't figure it out). The rooftop cools well enough, but are there more efficient options? Even a window shaker shoved in some space?

Our plan is to squeak by on a minimal budget while we learn. Save for a diesel conversion and have a plan before we are ready to convert her.

Thanks Mike & Jana

[Isuzusweet]

Ahhhh, another soon to be diesel convert; stay tuned on this channel for more info.

As for rubber bushings.....Take the old ones out and enter the sizes of the bushings into Google to see what different applications may also apply.

Cheers
Sidekick Tony

[mikeajana]

Tony, the whole reason we bought this Argosy is for the eventual Diesel conversion.
Wish there was a way to do the diesel, 4x4 and big tire conversion, but practicality gets in the way.
I'm watching your thread and can't wait for news.

I've spent way too much time researching these bushings and this Onan; WAY TOO Much.
I'll take any advice at this point.

[bkahler]

Originally Posted by mikeajana

Tony, the whole reason we bought this Argosy is for the eventual Diesel conversion.
Wish there was a way to do the diesel, 4x4 and big tire conversion, but practicality gets in the way.
I'm watching your thread and can't wait for news.

I've spent way too much time researching these bushings and this Onan; WAY TOO Much.
I'll take any advice at this point.

The density of the rubber bushings various whether it's for the generator end or the motor end. On Peanut I ended up upgrading the bushings to the later models which had higher density ratings. The early ones just aren't available at a price any human can afford.

My guess is the density on each end was increased over the years due to failures of the lighter density bushings. I've seen way to many rv generators that really sag and move around A LOT. I believe the worst that will happen with the higher density bushings is slightly more vibration. I'll know soon whether that's the case as I'm close to installing the Onan in Peanut using the new bushings.

Sometimes you just have to bite the bullet and pay the price.

Brad

[mikeajana]

Originally Posted by bkahler

On Peanut I ended up upgrading the bushings to the later models which had higher density ratings. The early ones just aren't available at a price any human can afford.
Brad

Brad, Can you share the part numbers you upgraded to? And did you find a more affordable source?

Thanks, Mike

[bkahler]

Originally Posted by mikeajana

Question number 1?
We have the Original Onan 4.0 BF C3R /1600 2B. There is a wire that provides power to the fuel pump and fuel shutoff valve. Mine is intermittent, and does not always provide what I assume is the prerequisite 12 volts. The Genset seems to be running fine, but I it "engineered" with a relay to provide power to the fuel pump (Amazon) and shutoff valve (antique original). Am I missing something? Not sure if the original wire provided something like overheat or low oil protection.

Thanks Mike & Jana

Where is the shutoff valve located? I don't recall seeing one before on an Onan but that doesn't mean they weren't installed. Of the three 4.0 and one 6.5 I haven't seen a shutoff valve. At least not that I remember, however I am getting older.....

The wire that provides power to the fuel pump is also the +12 feed to the coil. At least that's how it was originally wired. If you used that +12 wire to control a relay that turns on the fuel pump and shutoff solenoid that should work. Could you provide a sketch of how you have it wired right now?

Some Onan generators had low oil protection but I don't remember off the top of my head how the circuit was wired. I'll have to look up your model and see if I can find that information.

Brad

[mikeajana]

Sure. The fuel shutoff could have been a part of the original fuel pump/filter assembly. It had one wire that powered the fuel pump and opened the shutoff valve when 12 volts were applied. The wire came from inside the housing just below the fuses. In my picture it is the wire that goes up from the hole and bundled wires. it has a black cover and green zip tie. I installed a red wire and connector, it is disconnected in the picture.

The fuel shutoff is at the bottom of the second picture, Brass construction and inline before with the Amazon sourced fuel pump.

attached is also how I wired it. simple N.O. relay, closed by power from the ignition coil. While closed it provides battery 12v + to the fuel pump and shutoff valve.

[bkahler]

Originally Posted by mikeajana

Sure. The fuel shutoff could have been a part of the original fuel pump/filter assembly. It had one wire that powered the fuel pump and opened the shutoff valve when 12 volts were applied. The wire came from inside the housing just below the fuses. In my picture it is the wire that goes up from the hole and bundled wires. it has a black cover and green zip tie. I installed a red wire and connector, it is disconnected in the picture.

The fuel shutoff is at the bottom of the second picture, Brass construction and inline before with the Amazon sourced fuel pump.

attached is also how I wired it. simple N.O. relay, closed by power from the ignition coil. While closed it provides battery 12v + to the fuel pump and shutoff valve.

Looking through a bunch of Onan documentation it appears that shutoff valves were optional. I don't have any idea why some had them and some didn't. The solenoids are shown in varying ways on the diagrams. Your relay solution is a good one as it takes the load off the +12 vdc wire going to the coil. What I found was with the fuel pump connected to the same wire the voltage level was lower while starting and running which produces a weaker spark at the spark plugs.

Had the same issue on a Kohler generator and in the case of the Kohler I just removed the shutoff solenoid and it made a big difference in starting.

For the rubber vibration isolaters I ordered the following pieces:

upper vibration pads (3 each)

generator end vibration mount (1 each)

motor end vibration mount (2 each)

I don't remember for sure but I believe I ended up buying the last two from Lawn Mower Pros, possibly because Onanparts couldn't get them. Regardless the prices were around $15 each for the mounts and $5 each for the smaller ones on top.

Brad