kubota L3400 fuel problems

royyme · Sep 16, 2018

Tractor will run OK up to about 2500 RPM under light load. Under higher RPM and heavier load RPM slows to almost idle and will pick up some after a min. or 2 this cycle will start over again. Have no water in water separator bowl and fuel fills bowl fine when I replaced the filter in it.

mddorange · Sep 16, 2018

:welcome:
To TBN Royyme. You joined a great forum with very friendly and knowledgeable people.

This sounds like the problem I had last year. It was algae in the fuel. After I cleaned the bowl and replaced the fuel filter, I added a little Biocide treatment to my fuel tank and let it set overnight. The next morning it ran like it was new and I have not had a problem since. I do not treat every time but could if I needed to. I do treat after the fuel has set for awhile. It only takes about a 1/4 oz to treat a full tank.

ultrarunner · Sep 16, 2018

Which brand Biocide?

Had very good luck with Redline but last time I checked they no longer offer as they were told they needed an EPA Herbicide certification... I actually called the company.

My brother bought a Mercedes Diesel that had sat in a garage for a couple of years... it started and idled fine...

Problem was under load it starved for fuel... changed out the fuel filters about 5 times... then someone told him to add the Redline Biocide... this was 20 years ago and never a problem again...

royyme · Sep 16, 2018

Thanks, Mike will give that try.

mddorange · Sep 16, 2018

This is what I use: Fuel Additive STA-BIL Diesel Biocide 16 oz Gold Eagle From NAPA: https://www.napaonline.com/en/p/NCB22283

royyme · Sep 16, 2018

We have a NAPA here in town. Will be sure to pick up some tomorrow. Thanks again.

ultrarunner · Sep 16, 2018

Thank You!!

thepumpguysc · Sep 16, 2018

Roy.. u said it fills the filter "fine".. Whats FINE??
Theres no "majic fluid" that will fix all your problems..& theres no "liquid plumber" that'll clear the lines..
Pull the line coming off the fuel tank.. it NEEDS TO gush out.. put it back on & head down the line.. find where it DOESNT gush out..
& u have to give it time to FLOW.. just because u start to get wet or "some" fuel is coming out, doesn't cut it..

thepumpguysc · Sep 16, 2018

& when using a biocide.. it usually kills the critters & the dead carcass's end up clogging all your filters.. so if algae IS your problem, have some extra filters on hand.
Good luck.