My Generator Needs A New Fuel Pump

Wow...  what a talented family! Thanks for sharing.

RonJ

After 8 months, I am finally able to report that I replaced the fuel pump, fuel filter, and air filter, and all is well.

A few days ago when installing my new Alcoa wheels and flushing my brake system, I ran the generator to see if my "Runs For 20 Minutes, Then Dies" problem continued, and it repeated just as predicted.  Many months ago, I ordered the new parts, waiting for an opportune time to install them.

Wow, the project was a challenge for me.  This morning I still have indents on my right forearm.  I had to disconnect so much wiring and pull the wires and cables out from the compartment, just to be able to remove the solenoid, followed by the control board unit.  There is a connector with maybe 30 wires that plugs to the underside of the control board that is very hard to disconnect because of the confined work area.  Once disconnected, I was able to work it out with determination.  With the cables and wiring out of the work area and the solenoid and control unit removed, I could finally get to the fuel pump with fuel filter.

Once back together, I started up the generator, ran it for about 10 minutes without a load, then another 30 minutes with the a/c running and I am happy to say that all is well.

There are a few different fuel pump designs for sale.  I recommend one that looks like the original design as shown.


Because of the price and "supposed quality", I bought one that was styled like this.

It requires this elbow purchased separately.


It worked fine, but required filing the screw-mounting hole a tad bit more elongated to address a gentile interference problem.  The original design has no interference.

Nice job Ron! And as always, thanks for the useful info. 

Sounds like one heck of a job. You've written about many repairs and modifications you have done and you are obviously very skilled at this sort of a thing. 

I might have the skills to do it but I know I do not have the patience! .      Hopefully I never will never have it tested by this repair! 

How user friendly is the fuel filter? 

It’s mind boggling that Honda doesn’t own the rv generator market too. They really should  make a bolt in replacement for the green monsters.

How user friendly is the fuel filter? 

It’s mind boggling that Honda doesn’t own the rv generator market too. They really should  make a bolt in replacement for the green monsters.

  You're not kidding. Those Onan generators are such antiquated tech. Cummin ought to be ashamed.

Also, one has to wonder why they named something that is supposed to be a very reliable back-up after a biblical character who was anything BUT? https://en.wikipedia.org/wiki/Onan

I’m not sure A Honda gen would be the best alternative or that they’re interested in the market. Honda isn’t any quieter unless it’s an inverter/ gen which requires a heavy enclosure. That inside the enclosure of a motorhome will really restrict the air flow. So it would need to be a standard generator. I’ve seen onan gens with over 15,000 hours that have never been opened, carbs replaced yes. Now they claim inverter gens have a 3,000 hour life span. Even if it’s double their estimate it’s low in comparison.

I used to battle with this trying to think of ways to replace it with a Honda etc but for me that war is over.

How user friendly is the fuel filter?

Hmmmmmmm.......

I did not examine mine close enough to determine if the fuel filter can be easily serviced, but I think it can.  It would NOT take much investigation to determine that.

Here is a picture of the fuel filter.

The ribbed inlet on the left end protrudes outside the generator.  The fuel line connects outside the unit with easy access to disconnect it.  I would remove the fuel line and then the huge rubber grommet that the fuel filter passes through.  If the remaining hole is larger than the body of the fuel filter, you should be able to use a deep socket, unscrew it, and pull it out from the outside.  When screwing in the new filter, I would first wrap the threads with Teflon tape.

change the circuit board  I had the same problem  changed fuel filter/pump and stator    stopped working after a few mins  changed circuit board and my Onan now runs like a deer  good luck