Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  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 09-11-2011, 07:11 PM   #1
Junior Member
Newmar Owners Club
Ford Super Duty Owner
Join Date: Sep 2011
Location: Overland Park, KS
Posts: 27
Question Onan 7.5 Gas won't run on hot days

I have recently purchased a 1996 Newmar Kountry Aire gas MH with an Onan Emerald 7.5 KW gen set. The Onan is located in the right front storage compartment, just to the right and just behind the Ford 460 engine. We have just had a very hot summer here in the midwest. If the temperature outside is over 100 degrees (F), when we need the roof air the most, and we are driving the coach, the Onan will run for about 20 minutes, then surge once or twice and then die. It will not restart until after the day and the coach have cooled down. Then it takes a LOT of cranking (I assume to refill the fuel lines) before it will start again. If you don't drive the coach, it does not fail, if the temperature is under 95 degrees, it does not fail. We have replaced the fuel pump, but that did not fix the problem. I have double checked and the summer/winter lever is on summer, and the altitude compensator is set correctly. I have traced the fuel line and I don't see where it is getting close to the engine or exhaust system. I am sure that I'm getting a heat-related vapor lock, but does anyone have any suggestions for corrective action?

Chuck in Kansas City
1996 Newmar Kountry Aire
38' class A Motor Home
ChuckinKC 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 09-11-2011, 07:27 PM   #2
Senior Member
Join Date: Feb 2011
Location: Snowbird - Waterford Mi and Citrus Springs Fl.
Posts: 3,350
Maybe install a fuel pump back near the gas tank?

1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake
ahicks is online now   Reply With Quote
Old 09-11-2011, 07:42 PM   #3
Senior Member
az bound's Avatar
Workhorse Chassis Owner
Join Date: Dec 2007
Location: Surprise Arizona
Posts: 1,987
It is possible that it is shutting down due to inverter over temp. Try opening the inverter compartment. Also check that the inverter fan is running.
There is a part for Onans that can be installed to prevent vapor lock. Cant remember the part number but it is installed on the carbeurator.
Harold & Linda
2009 CT coachworks siena 35V
W22 Workhorse 8.1L. Explorer Sport toad,
az bound is offline   Reply With Quote

gas, onan

Currently Active Users Viewing This Thread: 1 (0 members and 1 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
Onan 7.5 Diesel Gen won't run C-PHartley Newmar Owner's Forum 10 07-11-2011 06:57 PM
Anyone know where to get aftermarket fuel pump for gas Onan HoRotica Class A Motorhome Discussions 8 05-14-2011 10:40 AM
to run hot water heater or not new rver iRV2.com General Discussion 7 08-27-2010 06:33 AM
Onan 7.5 won't start prpickett Newmar Owner's Forum 12 08-10-2010 07:49 AM
Onan 7.5 Quiet Diesel KIX MH-General Discussions & Problems 4 02-06-2010 04:16 PM

» Virginia Campgrounds

Reviews provided by

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:17 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.