onan 4000 fuel filter

[ADAD437]

anyone replaced the fuel filter on onan 4000, easy or hard? comments please from someone who has done it. thank's in advance.

[ADAD437]

CloudDriver wrote:
I had the fuel pump on our Onan 4KYFA26100K fail a few years back. On this model the filter is screwed into the suction port on the pump as shown in the pic below. The rubber fuel line goes onto the barb fitting on the filter, which is accessible from the side of the generator base. The filter can be replaced without removing the pump using a deep socket, which is (I think) a 9/16". I used a piece of dowel to plug the fuel line to prevent a siphon.



Onan # for the filter

interesting, yes i am having a problem with it. it will run about 3-5 minutes then start sputtering and quit, it will usually start back up fairly quick then die again.

[maillemaker]

This is the best forum for all things Onan:

https://www.smokstak.com/forum/forumdisplay.php?f=1

[CloudDriver]

I had the fuel pump on our Onan 4KYFA26100K fail a few years back. On this model the filter is screwed into the suction port on the pump as shown in the pic below. The rubber fuel line goes onto the barb fitting on the filter, which is accessible from the side of the generator base. The filter can be replaced without removing the pump using a deep socket, which is (I think) a 9/16". I used a piece of dowel to plug the fuel line to prevent a siphon.



Onan # for the filter

[Lincoln4]

Be sure to confirm only one fuel filter... I did my research on my Onan 7500, finding that it actually uses two fuel filters. That said they were easy to replace and I'm glad I did it myself. I simply used a pair of channel locks to pinch off the fuel supply.

You didn't really say what the reason for the filter replacement was... Just maintenance, or a problem? I was having a problem with the genny running for 10-15 minutes and quitting. After replacing the fuel filters and running a bunch of Seafoam through it, I learned of a problem with the fuel pumps used at the time of production. I replaced the fuel pump for about $25 bucks from Amazon, and it now runs like new.

[camperdave]

Fuel will not siphon from the tank, but you could clamp the rubber line to keep anything from draining out.

Are you replacing for general maintenance, or are you having an issue? I ask only in that with a 1/4 tank high pickup, it's highly unlikely that any junk is being pulled into the filter. If you are having an issue with it clogging, it is likely a bad fuel line, might be worth replacing any rubber lines between the pickup and the generator.

I replaced my filter while putting in a new fuel pump, so no experience on removing the filter only.

[DrewE]

ADAD437 wrote:

didn't check model, but not like yours.filter screws in on side and hard to get to, wondering if fuel will siphon from tank if line disconeticded from filter?

That probably depends mainly on how high your generator is in relation to the fuel tank.

One sure way to prevent siphoning fuel is to do the work when the fuel level in the tank is below about a quarter tank, and so lower than the generator pickup. At worse you'd drain the (relatively) small amount of fuel in the line between the tank and the generator.

[ADAD437]

ok looked, it is a RV QG4000 MODEL 4KYFA26100L.

[ADAD437]

maillemaker wrote:
Which model exactly?

Here is my 4BGE "Onan 4000"



You can see the fuel filter. You will want to unthread it carefully and thread on a new one and be careful not to cross-thread. It's easy to cross thread the metal tubing connector if it's not lined up exactly right.

Be sure to check for leaks after installing. Do not overtighten.

Steve

didn't check model, but not like yours.filter screws in on side and hard to get to, wondering if fuel will siphon from tank if line disconeticded from filter?

[maillemaker]

Which model exactly?

Here is my 4BGE "Onan 4000"



You can see the fuel filter. You will want to unthread it carefully and thread on a new one and be careful not to cross-thread. It's easy to cross thread the metal tubing connector if it's not lined up exactly right.

Be sure to check for leaks after installing. Do not overtighten.

Steve

[Lynnmor]

Try Youtube first.