Onan Generator Surging

[jimemeone]

I have the 7500 HDKAJ model and in starting it a couple days ago when the power went out in the RV park it would come off of high idle and then not run smoothly but would surge up and down so I just turned it off and waited for the power to come back on. I changed the fuel filter, oil filter and oil just 150 hours ago in 9/18 and last ran it about six weeks ago for a couple hours while doing a Walmart over night with no problems. So I think it might be a fuel filter or fuel pump problem but looking for some guidance from others that know this generator. Also, if it is the fuel pump I have not found any information on how to get to it and is it something I can work on myself.
Thanks in advance for all replies,
Jim & Diane 98' HRE 37'

[Twomed]

Try air filter first... Fuel pump Airtex E11020 on Amazon about $30 not too hard to change....depending on how the gen is positioned in your coach.

[Teamfoxy]

Surging is usually a carbuerator issue. Try running the SeaFoam treatment from a separate 1 gallon tank. It always works for me.

[C&SL]

Originally Posted by Teamfoxy

Surging is usually a carbuerator issue. Try running the SeaFoam treatment from a separate 1 gallon tank. It always works for me.

It is a diesel generator 🧐

I have seen some that had a in-line fuel filter right inside the housing where the fuel line connects to the generator. Not easy to see.

[vsheetz]

Change the fuel and air filters. Go from there.

[twinboat]

You can just take the air filter out and test run it, to see if it cures surging, although not likely the issue.

I would look at replacing the fuel filter.

[FatChance]

If the generator is on a slide out, pull out the slide and start the generator. If that allows it to run properly, crawl under and check the fuel lines for a kink or a pinched line. I had that same problem with the same generator and that was the cause. I rerouted the fuel lines and zip tied them in place and the problem is gone.