Does anyone know how to fix the fuel guage on a diesel generator belly tank?

[Bruce]

Thursday we had a big storm blow through that caused ~130,000 outages in Arkansas. ~19,000 of those were in our county disconnecting one out of every three homes. Entergy is estimating that power may not be restored until Tuesday.

So it was time go finally hook up the old rental fleet generator that I bought a few years ago. She is running great and powering the whole house.

Unfortunately the fuel guage on the 52 gallon belly tank seems to be stuck at 9/20ths of a tank. Based on adding 10 gallons of diesel this morning then being able to see diesel in the filler neck I believe the tank to be full.

Does anyone know how these guages work and have suggestions on how to get it working? I tried tapping on it but that was not successful.

Thanks for any advice.

This is the fuel guage in question. The generator is an old Multiquip DCA45 with an orange housing on a tandem axle trailer.

 

[Murf'n'surf]

Looks similar to the one on my Onan trailer genset. It has a float that rises and falls with the fuel. Unscrew it and find out.

 

[Bruce]

Looks similar to the one on my Onan trailer genset. It has a float that rises and falls with the fuel.

How do you access the float? Can I simply unscrew the gauge? Can I do so with the generator running?

 

[swatski]

Warning: Unnecessary Thread Hijack
@Bruce Obviously, time to upgrade to a new 242x. You could use solar panels on top of the bimini to power your household during situations like this.

--

 

[Murf'n'surf]

Yes, the actual gauge unscrews. Look underneath the gauge just to make sure.

You should be able to remove it as long as the fuel level isn't too high as it migh splash out from vibration.

 

[Bruce]

@swatski, I wish the 242x had enough solar panels to run my boat fridge!

@Murf'n'surf, thanks I am curious enough to go unscrew it.

 

[Bruce]

I started to unscrew the guage. Then fuel started flowing out. On the positive side that confirmed that it is full.

Then I lowered the tongue jack to shift the fuel to the front and was able to unscrew the gauge. Unfortunately there was crud and perhaps some corrosion on the vertical supports that the float slides on. I cleaned those up but am unable to remove the guage without separating the generator from the trailer.

The float does move up and down and the gauge moves with it. It seems to need calibration. There are screws holding the glass in place. I wonder if there is a way to calibrate it with the glass off?

On the negative side I now know that the fuel tank needs to be cleaned and I need to keep extra fuel filters on hand.

 

[Murf'n'surf]

I'm clueless on how it would calibrate.

 

[Bruce]

I'm clueless on how it would calibrate.

I suspect that calibration is by removing the float and reinstalling it with the needle at empty. But that is impossible without lifting the generator off of the trailer.

 

[Andy S]

@Bruce unless you can adjust the height of the float, the only other way I know how to calibrate a gauge like this is to pull the gauge needle off and resetting it in the correct place. You might need a needle puller similar to the one in the picture.