Good Sam Club Open Roads Forum: Onan Gen--hard starting and surging
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Class A Motorhomes

Open Roads Forum  >  Class A Motorhomes  >  Maintenance Issues & Tips

 > Onan Gen--hard starting and surging

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Prev  |  Next
10forty2

North Carolina

Senior Member

Joined: 07/08/2014

View Profile



Good Sam RV Club Member


Posted: 11/21/19 06:00am Link  |  Quote  |  Print  |  Notify Moderator

When we first got our coach, the genset would not run. It would turn over, but would not run. After a little studying, I figured out that it was getting plenty of fuel from the fuel pump, the fuel line was in good shape, and it had plenty of spark.....only thing left was the carb. I figured out how to disassemble the carb..removed the bowl...removed the needle valve and found the float to be slightly stuck in the closed position. Seafoam to the rescue! I put all the removed components in a bowl of Seafoam and let them soak for an hour or so, and then used a wire brush to remove all the varnish that had accumulated from the crappy gasoline. Put it all back together, and WAL-Ahh! She fired right up, ran like a sewing machine, and has been running great for the past 5 years. I put Seafoam in every tank of gasoline in the RV mixed at 1 oz per gallon of fuel. Primary engine runs great, and so does the genset!


1999 Holiday Rambler Endeavor, 36' Gasser
Triton V10, Ford F53 Chassis
-----------------------------------------


rrupert

NW PA

Senior Member

Joined: 02/26/2005

View Profile


Offline
Posted: 11/21/19 06:30am Link  |  Quote  |  Print  |  Notify Moderator

Check out the YouTube videos for Onan RV Generators:Onan


Rich and Joyce
2018 Jayco Jay Flight 21QB
2012 Ford F150 4X4 Supercrew EcoBoost
Reese Strait-Line Dual Cam Hitch
Amateur Radio K3EXU


RustyMacIntosh

Fresno, Cal

Full Member

Joined: 10/24/2019

View Profile


Offline
Posted: 11/21/19 01:08pm Link  |  Quote  |  Print  |  Notify Moderator

This morning it is spilling fuel from the air cleaner which mounts to the opening of the carb. I gotta get this carb torn down to check the needle and seat...

10forty2

North Carolina

Senior Member

Joined: 07/08/2014

View Profile



Good Sam RV Club Member


Posted: 11/21/19 01:29pm Link  |  Quote  |  Print  |  Notify Moderator

RustyMacIntosh wrote:

This morning it is spilling fuel from the air cleaner which mounts to the opening of the carb. I gotta get this carb torn down to check the needle and seat...


I'd bet the float valve is stuck open, allowing fuel to continuously flow into the bowl.

ksg5000

Oregon

Senior Member

Joined: 06/30/2008

View Profile



Posted: 11/21/19 02:28pm Link  |  Quote  |  Print  |  Notify Moderator

For what it's worth - soaking the carb with a bit of Seafoam for an hour isn't sufficient. You need to soak 8+ hours and then repeat as necessary. Your trying to remove 20 years of crud. If it were me I would load the carb with Seafoam and let it set at least a day.


Kevin

olfarmer

Iowa

Senior Member

Joined: 03/29/2006

View Profile



Good Sam RV Club Member

Offline
Posted: 11/22/19 08:33pm Link  |  Quote  |  Print  |  Notify Moderator

I would use some spray on carburetor cleaner rather than seafoam.


Ed & Ruby & the 2 cats
2001 Winnebago Brave 30W
7.4 gas Work Horse Chassis
99 Jeep Grand Cherokee


RustyMacIntosh

Fresno, Cal

Full Member

Joined: 10/24/2019

View Profile


Offline
Posted: 11/23/19 06:40am Link  |  Quote  |  Print  |  Notify Moderator

Going to give it a try today, I bought several cans of a brand name carb cleaner at Wallyworld once the sun is up, the dogs are satisfied, I will get my stool out then work on the carb.

RLS7201

Beautyful Downtown Gladstone, MO

Senior Member

Joined: 10/26/2002

View Profile


Offline
Posted: 11/25/19 11:07am Link  |  Quote  |  Print  |  Notify Moderator

Rusty if you have a 5K Onan in your 95 Bounder, it has been changed. In fact, I don't believe Onan made a 5K 120 volt gas generator for RV service. I sure would like to see a picture of the data tag on that generator.
95 Bounders came with an 4K BGE Onan with one Air Conditioner and a 7K NHM Onan with two Air Conditioners.

Richard


95 Bounder 32H F53
460/528 stroker
Web Master
MWPSchooners.com
First brake job
1941 Hudson


RustyMacIntosh

Fresno, Cal

Full Member

Joined: 10/24/2019

View Profile


Offline
Posted: 11/25/19 01:08pm Link  |  Quote  |  Print  |  Notify Moderator

it's[image] a 5000
I have douched the carb several times with Seafoam, letting it sit overnight. I would block off the inlet fuel line, let the genset run a few seconds, then pump Seafoam in that tiny plastic spray tube they supply, into the fuel line that runs to the carb.

Also, I took the air cleaner off the carb, spraying Seafoam all over the choke butterfly. Also let it sit overnight.

I think I fouled one plug. So I changed both spark plugs this morning, including dropping the extension and spark plug socket down the back of the generator.

This AM it fired up, smoked a bit then settled down to a nice idle. After it warmed up I turned one AC unit on. Everything was fine until I shut the AC off after letting the gen run for 30 minutes,

Then the surging began again. I am thinking for the time being to just fire it up several times a day letting it run as long as it can using clean fresh fuel from the main tank that has Techroline additive.

Sooner or later I am sure I am in for a carb replacement. Fuel filter is clear, the pump is pumping...it just does this surging thing then ultimately shuts down.

https://ibb.co/gJqgFjr

The gen has 501 hours on it btw.

* This post was edited 11/25/19 01:19pm by RustyMacIntosh *

77rollalong

Brighton Ontario

Senior Member

Joined: 02/03/2018

View Profile


Offline
Posted: 11/26/19 04:34am Link  |  Quote  |  Print  |  Notify Moderator

If it has sat for quit a while, best bet is to pull the carb off and get a container of the really good carb cleaner from napa or auto zone.. the one I got was marked professional use only, as it will dissolve plastic and rubber parts and wear rubber gloves, hard on skin.. like paint stripper.. there should be and adjustment for the idle mix on the carb you could try tweeking that a bit as well. Not sure if yours has an auto choke pull off from vacuum or not, mine is a heater type pull of so it takes a bit of messing about to get it right as well as it takes about 2 min to completely pull off when first started and runs a bit lumpy. ours is the original gen set in out 1977 motorhome ..

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Prev  |  Next

Open Roads Forum  >  Class A Motorhomes  >  Maintenance Issues & Tips

 > Onan Gen--hard starting and surging
Search:   Advanced Search

Search only in Class A Motorhomes


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2020 CWI, Inc. © 2020 Good Sam Enterprises, LLC. All Rights Reserved.