Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > RV SYSTEMS AND TECHNOLOGIES FORUMS > RV Systems & Appliances
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 10-18-2021, 09:21 PM   #1
Senior Member
 
CamJam1's Avatar
 
Join Date: Mar 2019
Location: Arizona
Posts: 2,210
Knock-off carburetors for Onan Generators

I'm in need of a carb rebuild on my Onan Marquis 7000. I stopped by our local RV dealer's service department today and was told that they're no longer able to rebuild carbs and that a new Onan carb is $400+. The service manager there said that they haven't had good luck with the cheap knock-off carbs on Amazon and suggested I buy a kit and rebuild it myself. In looking for a kit I saw numerous knock-off carbs for sale for around $60.00-- little more than the price of a rebuild kit-- and the reviews on Amazon were amazingly good. Just wondering if there are users on here who have tried these knockoffs and what they thought of them? For $60 bucks it might be worth a try, but these days I'm growing more and more skeptical about the legitimacy of on-line reviews from places like Amazon.
__________________
2004 National Dolphin LX 6320, W-22, 8.1, Allison 1000, Front/rear "Trac" Bars & Anti-sway Bars, Sumo Springs, Roadmaster Reflex Steering Stabilizer, 2005 PT Cruiser Toad
CamJam1 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 10-18-2021, 09:44 PM   #2
Senior Member
 
tap4154's Avatar
 
Join Date: Apr 2019
Posts: 1,951
Quote:
Originally Posted by CamJam1 View Post
I'm in need of a carb rebuild on my Onan Marquis 7000. I stopped by our local RV dealer's service department today and was told that they're no longer able to rebuild carbs and that a new Onan carb is $400+. The service manager there said that they haven't had good luck with the cheap knock-off carbs on Amazon and suggested I buy a kit and rebuild it myself. In looking for a kit I saw numerous knock-off carbs for sale for around $60.00-- little more than the price of a rebuild kit-- and the reviews on Amazon were amazingly good. Just wondering if there are users on here who have tried these knockoffs and what they thought of them? For $60 bucks it might be worth a try, but these days I'm growing more and more skeptical about the legitimacy of on-line reviews from places like Amazon.
Are you sure you need a carb rebuild? My folks had a Pace Arrow with an Onan Marquis in it, and they were told they needed a carb rebuild. I searched around and talked to a few mechanics, and ended up buying some Onan 4C, which unfortunately is no longer available.

I opened up the carburetor bowl drain and filled it up with the 4C, then closed it. Came back the next day and drained it (it was very nasty and dirty) and did the same thing again. Then the next day I drained it and primed it, and it started up and ran like brand new.

If you do some searches there's other carburetor cleaners that might be similar, but it would be worth a try. I still have the almost full can of 4C, and I feel like it's gold [emoji16]
tap4154 is offline   Reply With Quote
Old 10-18-2021, 10:29 PM   #3
Senior Member
 
CamJam1's Avatar
 
Join Date: Mar 2019
Location: Arizona
Posts: 2,210
Quote:
Originally Posted by tap4154 View Post
Are you sure you need a carb rebuild? My folks had a Pace Arrow with an Onan Marquis in it, and they were told they needed a carb rebuild. I searched around and talked to a few mechanics, and ended up buying some Onan 4C, which unfortunately is no longer available.

I opened up the carburetor bowl drain and filled it up with the 4C, then closed it. Came back the next day and drained it (it was very nasty and dirty) and did the same thing again. Then the next day I drained it and primed it, and it started up and ran like brand new.

If you do some searches there's other carburetor cleaners that might be similar, but it would be worth a try. I still have the almost full can of 4C, and I feel like it's gold [emoji16]
Thanks for that advice. A good cleaning would probably do it, though you just never know and I thought rebuilding it would be the prudent thing to do. Anyone here know a good alternative to the Onan 4C that tap4154 refers to?
__________________
2004 National Dolphin LX 6320, W-22, 8.1, Allison 1000, Front/rear "Trac" Bars & Anti-sway Bars, Sumo Springs, Roadmaster Reflex Steering Stabilizer, 2005 PT Cruiser Toad
CamJam1 is offline   Reply With Quote
Old 10-18-2021, 10:51 PM   #4
Senior Member
 
geordi's Avatar
 
Join Date: Jun 2018
Posts: 1,354
Probably seafoam. The other thing to do is to install a fuel shut-off valve on the fuel line near the generator and use THAT to kill the generator when you want to shut down for storage - run it out of fuel in the bowl. The ethanol in the fuel absorbs water and then when it evaporates, it leaves chalky deposits in the carb which can only be mechanically removed - and frequently NOT removed. The carb also should be adjustable but new ones are neither designed for rebuilding OR adjustable, thanks to our "friends" at CARB in California, who think that if someone could adjust the carburetor, they might make their engine burn less fuel (or more fuel or just run properly) and that's taking the control away from They Who Know Better, who designed it to run like crap so you'd just throw it away and buy a new one.

Can you tell I've been dealing with this on a gasser RV for a bit?
__________________
02 40' Monaco Diplomat: 1020 watts solar, Victron inverter. FASS, TRW steering, 23 cuft Frigidaire, D/W, W/D, Magneshade, Wood Floor, New cabinets, diesel heater
geordi is offline   Reply With Quote
Old 10-18-2021, 11:27 PM   #5
Senior Member
 
Bill Gail's Avatar
 
Join Date: Oct 2018
Location: The Great NorthWest
Posts: 1,130
Quote:
Originally Posted by CamJam1 View Post
I'm in need of a carb rebuild on my Onan Marquis 7000. I stopped by our local RV dealer's service department today and was told that they're no longer able to rebuild carbs and that a new Onan carb is $400+. The service manager there said that they haven't had good luck with the cheap knock-off carbs on Amazon and suggested I buy a kit and rebuild it myself. In looking for a kit I saw numerous knock-off carbs for sale for around $60.00-- little more than the price of a rebuild kit-- and the reviews on Amazon were amazingly good. Just wondering if there are users on here who have tried these knockoffs and what they thought of them? For $60 bucks it might be worth a try, but these days I'm growing more and more skeptical about the legitimacy of on-line reviews from places like Amazon.

From my research on the Onan carb replacement , I've read where people are purchasing the aftermarket carbs and just using the fuel bowls .

It appears the bowl and jet get gummed up from the ethanol fuel which causes the problem . So rather than pull the entire carb off they simply install the fuel bowl from the aftermarket carb onto the original carb body .

The results have been successful , saved a bunch of money and much easier to do than to pull the entire carb off .

A couple years ago I had mine replaced with the Onan factory carb for $600 .

I'm going to purchase an aftermarket carb and keep it in my spares for future use if necessary.
Bill Gail is offline   Reply With Quote
Old 10-18-2021, 11:53 PM   #6
Senior Member
 
Bobby F's Avatar
 
Join Date: Aug 2019
Location: MN
Posts: 2,809
Find an old dental waterpick. Disassemble the bowl and float, and pull out the needle valve. Spray the entire assembly with Seafoam, let it sit a few hours, and then blast out all openings with the waterpick. All you get in a rebuild kit, really, are new o-rings and gaskets, and if you disassemble with care the old ones should be fine.

Eventually the needle valve and seat will corrode and then you'll need replacements, but most carbs can be cleaned this way over and over.
__________________
------------------------------------

1993 Rockwood 28' Class C - Ford E-350 7.5L
Bobby F is offline   Reply With Quote
Old 10-19-2021, 11:12 AM   #7
Senior Member
 
CamJam1's Avatar
 
Join Date: Mar 2019
Location: Arizona
Posts: 2,210
I like the idea of putting the bowl from a knock-off onto the original carb! I'm first going to try cleaning the bowl and jet, but that will be my back-up plan. Thanks for the tip!
__________________
2004 National Dolphin LX 6320, W-22, 8.1, Allison 1000, Front/rear "Trac" Bars & Anti-sway Bars, Sumo Springs, Roadmaster Reflex Steering Stabilizer, 2005 PT Cruiser Toad
CamJam1 is offline   Reply With Quote
Old 10-19-2021, 01:23 PM   #8
Senior Member
 
Join Date: Jul 2014
Posts: 35,349
The bowl is just that, a bowl.

It has no passages that can clog up or needle valve that can stick.

Take off the bowl and take some fine stranded electrical wire and stick it up thru the center passage a few times. That cleans out the crud so that the correct amount of gas is sucked up.
Wipe out the bowl and put it back on.
twinboat is offline   Reply With Quote
Old 10-19-2021, 01:41 PM   #9
Senior Member
 
Join Date: Aug 2020
Location: Ohio
Posts: 2,353
Never replace Onan carb.. no no no.. unless badly damaged... they are made to be cleaned.. if you have a gas onan and you think carb is bad.. clean it.. so simple.. 90% of time you dont even have to remove carb..

Never replace.. clean.. then make small adjustments..

I clean on the eng.. pull off air cleaner.. use all safety precautions.. get spray carb cleaner 2 cans or so.. remove float bowl carefully.. and clean.. look into carb throat and spray cleaner in the tiny holes at top and bottom of throat.. the clean out bowl.. don't remove float.. count number of turns you make to turn out screw holding bowl to carb.. spray cleaner up inside main jet of carb.. that is where gas gets sucked up from bowl.. carefully spray float needle.. don't take apart.. take fuel line off.. and filter, if has one ... then spray though there..
Put bowl back on.. if you tare the gasket.. use RTV to seal carb bowl.. then start and adjust.. check output voltage..

There is a better even easier way to clean.. but I got to go.. maybe some else will tell us before I can get back with even simpler way.. also you tube KEVIN CAUDILL.. he shows piece by piece taking apart and cleaning
Good luck and let us know what you did and maybe better members then me will help you
__________________
2000 southwind storm, workhorse custom chassis with 7.4l vortec
donr103 is offline   Reply With Quote
Old 10-19-2021, 02:13 PM   #10
Senior Member
 
Winnebago Owners Club
Join Date: Sep 2015
Posts: 1,810
I worked on my Onan Marquis 5500 when it quit running. I could not even get a rebuild kit. Not sure exactly what model you have, but I ordered what was supposed to be an exact replacement for my carb, and it wasn't even close to fitting. Then I tore mine apart. The bowl was completely full of white pasty stuff. Cleaned it up. Spotless and all jets clean and free, float cleaned and free. Put it back on, would fire but not run. $360 for an OEM carb. Bolted it on. Started on the second crank and ran like new. I probably wasted 15 hours. Another time, I would just order the right carb from Onan and be done.

Sold that motorhome but talked to the guy that bought it and he has put over 500 hours on it. Still runs perfect.

Quick Edit: Did a search and the "Onan" carb kits and the China carbs are not even close to what my Marquis Gold 5500 had on it. I can tell just by looking none of the carbs listed would even bolt to the gen that I had.
__________________
2006 Winnebago Journey
39K
Cat C7
amosnandy is offline   Reply With Quote
Old 10-19-2021, 03:23 PM   #11
Senior Member
 
Bobby F's Avatar
 
Join Date: Aug 2019
Location: MN
Posts: 2,809
Quote:
Originally Posted by twinboat View Post
It has no passages that can clog up or needle valve that can stick.
An Onan carb has no float?
__________________
------------------------------------

1993 Rockwood 28' Class C - Ford E-350 7.5L
Bobby F is offline   Reply With Quote
Old 10-19-2021, 04:27 PM   #12
Senior Member
 
WagonMaster's Avatar
 
Join Date: Aug 2002
Location: Yukon, OK, USA
Posts: 447
I don't know about Onan, but I've been using those knock off carb's ffrom Amazon for my chainsaw, weedeater, etc, with great results. For $60.00 bucks I'd give it a try
__________________
2014 Big Country 3650RL
2011 Chevy 3500HD, DRW, 4 X 4
Retired, 3 Boston Terriers
WagonMaster is offline   Reply With Quote
Old 10-19-2021, 05:35 PM   #13
Senior Member
 
Join Date: May 2016
Posts: 846
And I put a knockoff from Amazon on my house/construction generator (Briggs and Stratton engine) and it worked like a charm. Still does. Ran it on a job yesterday for over six hours. Starts on second pull.
__________________
Marvin (and Eileen) - 1997 34’ Gas Bounder / 1996 F53 Chassis | Towing 1996 Ford Ranger on Acme Dolly
MarvinG is offline   Reply With Quote
Old 10-19-2021, 06:02 PM   #14
Senior Member
 
Join Date: Aug 2020
Location: Ohio
Posts: 2,353
So.. back.. my super fast way to clean carb.. works 50% of time.. pull fuel hose and filter if has one on carb.. spray good carb cleaner in the fuel inlet.. reconnect.. remove air cleaner and housing.. use all safety precautions... spray cleaner in throat of carb.. main objective is those tiny holes in top of throat and the big one in bottom center..
Next.. find flat plate.. or scrap plastic.. to cover carb opening.. make sure what you use will not get sucked in.. no rags.. use stiff, hard plastic.. to big to get sucked in..
Start gen.. let warm up.. then cover throat of carb.. and choke eng down but don't stall..then repeat manually choking down.. about 3 times..
Then make small main jet adjustments until runs smooth.. check output voltage..
Make sure armature slip rings are nice and shiny..
Put back together and see if ok.. then add fuel injection cleaner to fuel.. error on the heavy side.. with fuel injection cleaner.. depending on how full tank is..
Then run gen enough to get injection cleaner in it..
This procedure pulls the trash plugging main jet up and out.. and that is the idea..
90% of time it's the main jet that gets vanished in it.. so if you can rush the cleaner you sprayed in bowl.. up through main jet by choking eng out.. most of the varnish gets pulled out and cleans main jet..
If carb is badly varnish.. removal and complete tear down to main jet cleaning

As always good luck and let us know what you did and maybe better members then me will help you
__________________
2000 southwind storm, workhorse custom chassis with 7.4l vortec
donr103 is offline   Reply With Quote
Reply

Tags
generator, onan, generators



Currently Active Users Viewing This Thread: 2 (0 members and 2 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Generators: Use Onan, RV generators for stick homes? Oldedit iRV2.com General Discussion 16 03-19-2021 10:04 AM
Carburetors! What do you know about them? Chieftain27 RV Systems & Appliances 133 11-02-2020 02:38 PM
Cheap Front Sumo Clone ? JIMBO34PA Ford Motorhome Chassis Forum 11 10-10-2020 09:31 AM
Tech2 (Clone) Scanner olskool4x4 Workhorse and Chevrolet Chassis Motorhome Forum 15 01-04-2019 04:27 AM
Altitude Compensating Carburetors Possum Vintage RV's 27 07-11-2012 01:03 AM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 01:45 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.