Good Sam Club Open Roads Forum: Update on the Onan Marquis 5000 generator
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 > Update on the Onan Marquis 5000 generator

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RustyMacIntosh

Fresno, Cal

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Posted: 02/04/20 06:25am Link  |  Quote  |  Print  |  Notify Moderator

This is a factory installed Onan in my gifted 96 Bounder. The coach sat for a long time in storage. It was occasionally used. Then gifted to me by the adopted kids girlfriend and her family.

So after 4000 miles of tooling around California working the bugs out of the coach, ie, tires, shocks, brakes, suspension, the generator has always been a PITA.

I've had that carb off countless times douching it with Seafoam. Never did I force the black bowl off at the bottom of the carb. It would run, then surge then die. Sometimes within 10 minutes sometimes after hours.

So determined to figure this out, and not wishing to drop a grand at the dealer, the other night it was running then quit. I immediately pulled the fuel line and cranked the starter. NO FUEL.

The fuel pump was removed. Attached to the old style Carter fuel pump was this gas regulator. It had 2 black wires attached to it.

I went to the dealer to see what a new carb would run. ($400). That regulator might have had something to do with LP gas. Not sure. Parts guy was clueless.

The service guy told me to go to NAPA buy an aftermarket pump, install it, see what happens. I did. The gen ran but was being overpowered by the flow. Black smoke and gas coming from the air filter housing. I squeezed off the line, choking off the fuel flow it smoothed out and ran.

I then installed an old school universal fuel regulator. I dialed it down to 1.

Gen sat and ran. 2-3 hours it ran. Only once did it hickup. So I still need a carb, but for now it seems to be running enough that in the mornings we can perk a coffee pot, then go back to battery and gas.

I was told that a rebuild kit is available for this unit, but I would rather just drop a new carb on this unit. So far, all I see online is $350ish or so.

I might, within a day or two after running the generator for a while to see how it likes the Eldebrock electric fuel pump, go for a new carb.

I think I might have bought the wrong pump that runs 4-7lbs. I should have paid more attention to the selection, I should have bought the low low powered pump but this universal regulator seems to be working.

Of course, an extension cord to the side door, the suitcase Harbor Freight 2k generator connected is always an option...but it's all about coffee in the mornings....

coffee...once there is fresh coffee....then life begins.

Dutch_12078

Winters south, summers north

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Posted: 02/04/20 06:50am Link  |  Quote  |  Print  |  Notify Moderator

That's a fuel shut off solenoid valve attached to the Carter fuel pump. A 4-7 PSI fuel pump should work fine on your 5000 without an added regulator. If it's flooding at that pressure, the float valve assembly in the carb bowl is faulty. I'm using an aftermarket replacement on mine that was about $15 on Amazon.


Dutch
2001 GBM Landau 34' Class A
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RustyMacIntosh

Fresno, Cal

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Posted: 02/04/20 06:54am Link  |  Quote  |  Print  |  Notify Moderator

what I did was put in another fuel pump, the Carter pump is in a box in the back of my C-Max. I put in a fuel pump from Napa. Eldabrock I think. It is grounded to the frame, the red to that white wire that comes from what looks like a starter solenoid way up behind the Genset,

the new pump was overpowering the float in the carb which is probably worn out anyway. So I installed another aftermarket product, a universal fuel regulator off my boat, to tone down the pressure to the carb.

I know I am in for a carb replacement. When I had that carb off in my hands, I did not remove the bowl. It is black and looks plastic.

enblethen

Moses Lake, WA

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Posted: 02/04/20 07:22am Link  |  Quote  |  Print  |  Notify Moderator

Do you have the Onan part number? What is model number of genset including the Spec letter?
Amazon has many Onan parts:
Carb


Bud
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rgatijnet1

Florida

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Posted: 02/04/20 07:23am Link  |  Quote  |  Print  |  Notify Moderator

Unless the carb has a lot of hours on it and all of the bushings are loose, then a rebuild is just as good as buying a new carb, and a lot cheaper. If the butterfly shaft is loose and sloppy then a new carb is needed but if they are still tight, just rebuild it yourself or have a carb shop do it. Make sure that all of float adjustments are right.

K Charles

Connecticut

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Posted: 02/04/20 07:27am Link  |  Quote  |  Print  |  Notify Moderator

If you didn't remove the bowl you didn't clean the carb yet. Maybe all you need to do is clean the carb, if it sat a long time the gas may have gumed up.





RustyMacIntosh

Fresno, Cal

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Posted: 02/04/20 07:48am Link  |  Quote  |  Print  |  Notify Moderator

enblethen wrote:

Do you have the Onan part number? What is model number of genset including the Spec letter?
Amazon has many Onan parts:
Carb



5BGMFA26105F

H953416019

RustyMacIntosh

Fresno, Cal

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Posted: 02/04/20 07:52am Link  |  Quote  |  Print  |  Notify Moderator

https://postimg.cc/sQ9pPX6m

Pix of the generator


https://postimg.cc/34HXDpBW


Generator label

enblethen

Moses Lake, WA

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Posted: 02/04/20 08:40am Link  |  Quote  |  Print  |  Notify Moderator

Found this parts manual. Page 19 item 46
Parts manual
Pricey little things!
Amazon

RLS7201

Beautyful Downtown Gladstone, MO

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Posted: 02/04/20 08:41am Link  |  Quote  |  Print  |  Notify Moderator

Also, when identifying the generator, it's a 5500 not a 5000. Make a difference when asking for help.

Richard


95 Bounder 32H F53
460/528 stroker
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