ONAN The Barbarian

[PoppySteve]

My 4000 gas model is not running smoothly. I have tried all the DIY maintenance and thinking about taking it to the ONAN mechanic.

If you have gone this route for a fix, have you been satisfied with the result?

[wmtire]

I have no help for you, but as a site team member, I do want to comment that yours is one of the more creative thread titles. I really got a kick from it.

[Iggy]

How many hours on the generator?
Have you tried carborator cleaner sprays?
What altitude are you at? You know about the adjustment?
Have you tried this stuff in your gas tank on the next trip?
Berryman's B-12?
1 can per 20 gallons of gas. (80 gallong - 5 cans)
You probably have a 55 gallon tank so 3 cans would be good.
But do it when you plan a good long trip ont he road.
I add this stuff in my gas tank and run my generator for awhile under load and ensure the generator gets warmed up good.

This stuff clears the lines, filter hoses and carb from built up varnish when you have gas sitting for a long time.

$3.47 a can at Walmart

[PoppySteve]

Well thanks wmtire. I try to add a little humor when I can!

And Iggy, thanks for the suggestion. I used seafoam/gas solution direct from a 2 gallon gas jug with not much luck. 385 hours at 250 sea level.

I was just wondering if any ONAN service was worthwhile.

[Iggy]

Originally Posted by PoppySteve

Well thanks wmtire. I try to add a little humor when I can!

And Iggy, thanks for the suggestion. I used seafoam/gas solution direct from a 2 gallon gas jug with not much luck. 385 hours at 250 sea level.

I was just wondering if any ONAN service was worthwhile.

Seafoam is ok but if you search Berryman's B-12 to see the difference it worht a $12 before going to an Onan dealer.

They will probably charge you a few hundred just to look at it and then replace what they think is the problem.

It the needle valve adjustment on the carborator knob set at sea level?


Here is a writeup from someone who had similiar issues. Please read.

https://www.irv2.com/forums/f84/onan...es-256397.html
Good luck.

[PoppySteve]

Yes needle valve set at sea level.

I might try the B-12.

Thanks for the link to the post. I am a DIY guy so might try some of those things and see how it goes.

[nayther]

where are you getting gas? Some states allow up to 15% ethanol in their gas. Ethanol is attracts moisture and can eat up rubber fuel lines that are not rated for use with it. The rubber breaks down and can clog jets. I had a 2007 toy hauler with Onan 5500 and found the rubber hoses were very soft to the touch. Trailer was built before wide spread use of ethanol and the knowledge of what happens to older engines. If you read the warning on a pump it will state it is not to be used in older vehicles, a real problem for lawn mowers, pre-FI motorcyles, etc.